De Somfy Factor Part #2 UK

The Somfy Factor Part 2
Reducing energy consumption and CO2 emissions
in non-residential buildings using dynamic solar shading
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A shining example.
The jellyfish.
Unloved.
And therefore unknown.
Entirely unfairly.
The jellyfish can actually teach us a lot.
About light absorption.
About transparency.
And about bioluminescence.
In other words, an organism’s ability
to generate its own light.
Using the jellyfish as a shining example,
Somfy developed something unique.
Technology that lets buildings play
with light in an unusual way.
Letting them anticipate light and shade.
Bringing outdoor light and interior lighting
together harmoniously.
As a way of creating a pleasant
climate indoors.
One that is sustainable as well as providing
an optimum feeling of comfort and well-being:
the Somfy Factor.
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CONTENTS
The Somfy Factor Part 2
Reducing energy consumption and CO2 emissions in non-residential
buildings using dynamic solar shading
Foreword 10
1 Sustainable development 13
2 Climate and sustainability in the Netherlands 27
3 Climate legislation 37
4 Emissions of greenhouse gases 65
5 Energy consumption and emissions of buildings
and construction activities 79
6 Certification for utility construction 103
7 Glass, façades and dynamic shading 123
8 Properties of technical fabrics in dynamic shading systems 143
Appendices 161
9 Parametric design 173
10 Model for energy consumption and CO2 emissions
in an office space 183
11 Productivity and energy effects of dynamic solar and
light shading in office buildings 195
Appendices 227
12 Sustainability as the top priority 241
Supplement – Roderik Henderson 245
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FOREWORD
A promise is a promise, of course, so here is Part 2 of The Somfy Factor.
The underpinning leitmotif for this, the second book, is the sustainability
of society. In the meantime, thousands of scientists around the world
have done a great deal of work to map out the human race’s influences
on the climate and the environment, and how they are changing.
The need to take action has now given rise to numerous new laws that
directly or indirectly affect everyone on Earth. Their influences will be felt
progressively in the years to come.
Research has shown that buildings have a significant impact on climate
change, so all kinds of efforts are being made to minimise or preferably
eliminate those impacts. The effects arise partly from the construction
work itself and the production of the building materials, but to a much
greater extent during use.
The impact during use is basically about the energy consumption for
lighting, heating and cooling of buildings. Such considerations quickly
take us to buildings’ façades – the walls with windows, whose functions
include allowing daylight to get in. This obviously influences the use
of artificial light heavily, and it also affects the temperature inside the
building.
We examined the influence of daylight on temperature and other indoor
environment parameters. It is evident that some way of controlling the
daylight in buildings is indispensable. It can be tackled in various ways,
of course, including the use of dynamic solar shading.
The book describes the creation of an integrated model for identifying
the way dynamic solar shading influences the indoor environmental
parameters, energy consumption and CO2 emissions of individual office
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uildings. The model quantifies the costs and benefits for office buildings,
aiming to make the model a tool that will help people make betterinformed
decisions about applying dynamic shading in office buildings.
The knowledge acquired is now being utilised to make the model
applicable to buildings in other domains as well, specifically the
education and healthcare sectors. The model has also been designed
so that various climate plug-ins can let it be used in other countries too.
This was needed not only because the results depend strongly on the
geographical location of the building and are therefore country-specific,
but also because other parameters such as the costs require local
adjustments if good results are to be obtained.
Sven van Witzenburg
Hoofddorp, March 2022
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SUSTAINABLE DEVELOPMENT
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THE GLOBAL SUSTAINABLE DEVELOPMENT AGENDA
The Sustainable Development Goals (SDGs) were defined in 2015 by the United Nations as the new
global sustainable development agenda for 2030. They are promoted as sustainable development
goals for use throughout the world. The SDGs apply from 2016 to 2030, replacing the Millennium
Development Goals that lapsed at the end of 2015.
In total, there are 17 goals and 169 underlying
objectives for achieving them. The 193 member states
who signed up to the policy are expected to translate it
into their national policies.
To monitor progress, a list of indicators has been drawn
up in a UN context: the Sustainable Development Goals
Indicators.
Status of the SDGs in the Netherlands
The Netherlands already has various objectives and
policy programmes in place in domains such as nature
and the environment; these are in line with the SDGs.
Statistics Netherlands conducted a baseline
measurement in November 2016 of how the
Netherlands is progressing with the SDGs.
This study was prompted by a list of preliminary
indicators for monitoring the various lower-level
objectives of the SDGs. The overall picture that
emerges from the figures available to date is that
the Netherlands is doing well in many areas but that
there are also significant areas of concern.
According to a report issued in May 2020, the
Netherlands scores relatively well on achieving
the sustainable development goals. The country
has achieved 26 of the 169 sub-goals, with only
Scandinavia and a few other European countries doing
any better. Areas for improvement for the Netherlands
are in particular the thirteenth goal (climate action);
the country could also score better on the fifth goal
(gender equality). So there are still developments
to be made.
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SUSTAINABLE DEVELOPMENT GOALS
SDG 1:
No Poverty
The first goal is the eradication of poverty.
According to the United Nations, it is also
the most important objective. Nobody
should be left behind in extreme poverty by
2030. Under the Millennium Development
Goals, extreme poverty meant having less
than 1.25 dollars a day to spend. The World
Bank raised that limit to $1.90 per day in
2015. In 2012, 12.8 per cent of the world
population lived under that poverty line of
$1.90 – that’s 896 million people. In 1990,
37 per cent of the world's population (or 1.95
billion people at the time) still lived below
this threshold.
The number is expected to have dropped to
9.5 per cent of the world’s population or 702
million people by 2015.
This goal has a total of seven objectives,
five of which must be achieved by 2030; the
last two have no specific end dates but can
be seen as long-term aims.
SDG 2:
Zero Hunger
By 2030, no one in the world should be
going hungry. Everyone must have access
to sufficient safe and nutritious food all
year round. According to the World Food
Programme, 795 million people currently do
not have enough food to live healthy and
active lives. That is about one person in
nine, worldwide. Sub-Saharan Africa has the
highest proportion of people suffering from
hunger: one in four people in that region is
malnourished. Almost half (45 per cent) of
all deaths among children aged under five
are also due to malnutrition. Around the
world, 66 million primary school children still
go to school hungry. This goal consists of
eight objectives and fourteen ambitions that
are related not only to ending malnutrition
but also to producing sustainable food
sources and to investments, research
and new technologies. A study published
in Nature has however shown that ending
malnutrition by 2030 already seems
impossible.
SDG 3:
Good Health and Well-being
Goal three is about health and well-being
for everyone, from young to old. According
to the World Health Organization, the infant
mortality rate in 2015 had fallen by 53%
compared to 1990. Nevertheless, six million
children still die before the age of five every
year. The majority of those children live in
Asia and sub-Saharan Africa. Four fifths of
the children who die before the age of five
come from those regions. Maternal mortality
dropped by 44 per cent by 2015 with respect
to 1990, according to the World Health
Organization, but advances are still possible
there too. The maternal mortality figure in
developing countries is still fourteen times
higher than in developed countries.
In addition to the topics just mentioned,
the third goal’s agenda also deals with
the impact of diseases that cannot be
transmitted from person to person,
accidents, pollution and universal
healthcare.
SDG 4:
Quality Education
The Millennium Development Goals in
particular have led to big improvements
in education in recent years, above all for
women and girls. Currently, 91 per cent of
children in developing countries attend
primary school. The number of children not
attending school has halved since 2000:
from 100 million then to 57 million in 2015.
Fifty per cent of the children of primary
school age who do not go to school live in
conflict zones.
About 103 million young people worldwide
are still illiterate.
The fourth goal comprises ten objectives
and eleven indicators. The objectives
include not only free primary education,
good secondary and higher education but
also fighting discrimination in education
and illiteracy, as well as promoting
education about sustainability.
SDG 5:
Gender Equality
The Universal Declaration of Human Rights
states that men and women have the same
rights. “Equality between men and women
is not only a human right but also the basis
for a peaceful, prosperous and sustainable
world,” according to the United Nations. In
practice, though, women and girls are still
often at a disadvantage compared to men
and boys. The fifth goal states that by 2030
women and men should have equal rights to
facilities such as education, healthcare and
employment. Moreover, women and men
must be equally represented in political and
economic decision-making.
The fifth sustainability goal comprises nine
targets, dealing inter alia with ending discrimination,
violence and exploitation of women,
genital mutilation and forced marriages.
SDG 6:
Clean Water and Sanitation
Clean drinking water and proper, clean
sanitation have a positive impact on
other Global Goals such as food security,
education and health. There are fewer
infections if clean drinking water is
available, and clean toilets in schools
mean that more girls keep going to school
even when they are menstruating. There is
enough clean drinking water in the world
for everyone, but problems such as poor
infrastructure or a weak economy mean
that millions still die every year from
diseases caused by polluted drinking water
or poor hygiene.
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Since 1990, 2.6 billion people have been
given access to clean drinking water, but 1.8
billion people still get their drinking water
from polluted sources. On top of that, 2.4
billion people in the world still do not have
access to clean toilets and other sanitary
facilities.
The sixth sustainability goal has six
different targets dealing with drinking water,
sanitation or hygiene, for example, through
a programme that promotes not only hand
hygiene but also efficient use of water
and the search for ways to filter and store
drinking water.
SDG 7:
Affordable and Clean Energy
We need energy for our prosperity and
wellbeing: for living, in our homes and at
our work. Society could not have developed
to be what it is today without energy. That
is why it is important for everyone to have
access to energy. One in every five people
currently does not have access to energy,
yet at the same time, energy is one of
the biggest problems for the twenty-first
century. We get too much of our energy from
coal, oil and gas; these fossil fuel resources
will run out sooner or later and they are
causing climate change. At least 60% of
greenhouse gas emissions are the result of
energy generation.
The objectives include access to affordable
and reliable energy, with a key role
envisaged for technology to improve energy
production and storage.
SDG 8:
Decent Work and Economic Growth
In many countries, having a job does not
necessarily mean that you can escape
poverty. That is why goal number eight
focuses on decent work for all and
sustainable and inclusive economic
growth. This means that everyone who
can work should have the opportunity
to work, with good working conditions.
These jobs should encourage economic
growth without harming the environment.
One of the targets for 2020 was reducing
unemployment among young people.
The eighth sustainability goal also helps
strengthen financial institutions so that
they can promote sustainable economic
development.
SDG 9:
Industry, Innovation and
Infrastructure
Infrastructure means transport, roads,
irrigation, energy and ICT.
If improvements are to be made in
education, healthcare or drinking water,
infrastructure is needed. Without roads and
transport, for instance, it is much more
difficult for children from remote villages
to go to school. Many developing countries
do not have this basic infrastructure and
without it, getting a job, doing business,
receiving information and fetching bread
are all harder. In other words, better
infrastructure makes it easier to achieve
other objectives and improves the quality of
life overall.
There are seven targets dealing with
infrastructure and industrialisation. One of
those objectives is about getting mobile
signals for better connectivity.
SDG 10:
Reduced Inequality
Inequality in income between countries has
been reduced during the first decade of the
21st century. Inequality within countries,
though, has only increased. Between
1990 and 2010, inequality of income
within developing countries rose by 11%.
And income inequality within developed
countries has risen too. Realisation that
economic progress alone is not enough to
combat poverty is increasing worldwide.
Economic growth has to be inclusive, i.e.
everyone has to be involved. The concept
of ‘economic growth’ also has to include
paying attention to social aspects and to
the environment. This development goal
comprises ten objectives that are about
reducing inequality between people, and
that can refer to social, economic, financial
or political inequality. They can also be
about having equal opportunities and
ending discrimination.
SDG 11:
Sustainable Cities and
Communities
Half the world's population – some 3.5
billion people – live in cities and that
proportion is expected to grow: nearly 60
per cent of the world’s population may
be living in urban areas by 2030. Almost
all of that urbanisation (95 per cent) is
happening in developing countries and the
growth of urban areas is taking place in
slums. Some 823 million people live in such
neighbourhoods now, but the number is
expected to keep growing.
This goal is mostly about the development
of cities. It is important that this
development strikes a balance between
social, economic and environmental
sustainability.
Particularly during the Covid-19 pandemic,
it became clear that many infections with
the virus could be traced back to densely
populated areas. Additionally, this goal
addresses the development of career
opportunities, transport and handling
natural disasters.
SDG 12:
Responsible Consumption and
Production
Ensuring sustainable management and
efficient use of natural resources.
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Given the growing world population, we
have to produce our goods in much more
sophisticated ways – ‘producing more
with less’.
This goal has eleven targets that deal with
ecological improvement of current food
production methods, as well as waste
reduction. It is important to produce food
sustainably in order to preserve nature
and reduce our material footprint, thereby
having a positive effect on the climate.
SDG 13:
Climate Action
Every country on every continent is being
affected by climate change. Global warming
is already affecting the daily lives and
incomes of millions of people worldwide and
this is only going to increase in the future.
This goal aims to tackle climate change
through five targets that attempt to
prevent climate disasters, increase our
understanding and focus on policies for
getting a grip on the problem worldwide.
SDG 15:
Life On Land
This goal is about protecting, restoring and
promoting sustainable use of ecosystems,
managing forests sustainably, combating
desertification and land degradation and
bringing biodiversity loss to a halt.
Woodland and forests cover 30 per cent of
the Earth’s land surface. As well as being
important for food security and providing
shelter, they are essential for combating
climate change and protecting biodiversity
and they are the habitat of various
indigenous peoples. We are losing 13 million
hectares of forests every year and land
degradation is causing the desertification of
3.6 billion hectares of land.
The development goal has twelve targets, all
related to life on land. Plants are important
for people and animals as food; agriculture
is an important source of plants. Moreover,
some species are in danger of disappearing,
which can affect the ecosystem and
endanger other species.
Feeling safe and secure is a basic need.
Exploitation and human trafficking is one
example of a target, but aspects such as
enforcement and compliance with the law
can also be considered. Voting rights and
participation, the feeling of having a voice
that is heard in society, are also part of this.
SDG 17:
Partnerships for the Goals
The last development goal consists of
five different categories that in turn
consist of targets in finance, technology,
trade and systems, as well as support for
self-development. This goal is essentially
about cooperation between countries
and it attempts to promote policies for
sustainability.
For all five secondary targets, it is important
that the initiatives are launched properly
and sustainably, looking at how the targets
can be achieved for each country and
between countries and sectors as fairly
as possible.
SDG 14:
Life Below Water
The oceans, with their reservoir of heat,
their currents and their undersea life, are
the engine of the global systems that make
the Earth habitable for humans. They cover
three quarters of the Earth’s surface.
Our drinking water, our weather, climate,
the coasts, much of our food and even the
air that we breathe are all dependent on
the seas.
There are ten objectives for the
development goal about water. These cover
aspects such as pollution and protection
of the ecosystems e.g. by avoiding overfishing.
Pollution in the water is particularly
important, given that a great deal of plastic
worldwide ends up in the seas.
SDG 16:
Peace, Justice, and Strong
Institutions
The aim is to encourage peaceful and
inclusive societies with a view to sustainable
development. The Millennium Development
Goals did not pay much attention to this,
but almost everyone now agrees that
development is all but impossible without
peace, security and justice. Corruption, theft
and tax evasion cost developing countries
$1.26 billion a year – money that could be
put to good use tackling poverty or letting
children go to school. Half of primary school
pupils in conflict zones leave school without
any form of diploma. Peace, justice and
strong public services lead to development
and vice versa. They reinforce each other.
The development goal list sixteen targets
that deal with violence, peace and equality.
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Since its inception in 2015, the UN’s Agenda for 2030 has
been a blueprint for shared prosperity in a sustainable
world, one in which all people can live productive, active
and peaceful lives on a healthy planet. It will be 2030
in just under a decade from now and the question
is whether our actions today are laying appropriate
foundations for achieving the sustainable development
goals (SDGs).
The SDGs are a universal call to action for ending
poverty, protecting the planet and improving the lives
and prospects of everyone everywhere. The 17 goals were
adopted in 2015 by all UN member states as part of the
2030 Agenda for Sustainable Development, which sets
out a fifteen-year plan for achieving them.
Targets related directly to climate change
On closer examination, not many of the SDGs are directly
related to climate change. The goals directly related to
that theme are numbers 7, 9, 11 and 13.
SDG 7:
Affordable and Clean Energy
Even today, 13% of the world's population still has no
access to modern electricity. Three billion people depend
on wood, coal or animal waste for cooking and heating.
Energy is the main driver of climate change, accounting
for about 60% of total global greenhouse gas emissions.
Indoor air pollution from using flammable fuels for
household energy caused 4.3 million deaths in 2012, six
out of ten of which were women or girls. The share of
renewable energy in overall net energy consumption was
only 17.5% in 2015.
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SDG 9:
Industry, Innovation and Infrastructure
It has long been known that growth in productivity and
incomes and improvements in health and education
outcomes all need investment in infrastructure.
Manufacturing operations are an important driver of
economic development and employment. Another
important factor to consider is the carbon dioxide
emitted by production processes. Emissions have fallen
in many countries over the last decade but the rate of
decline has not been consistent throughout the world.
Technological progress is the foundation underpinning
the efforts to achieve environmental goals, such as
increasing the additional resources and improving energy
efficiency. Without technology and innovation, there will
be no industrialisation – and without industrialisation,
there will be no development. To increase efficiency
and focus on mobile cellular services that improve the
connections between people, more investment is needed
in the high-tech products that dominate production.
SDG 11:
Sustainable Cities and Communities
Half of all humanity – 3.5 billion people – lives in cities
today and 5 billion people are expected to be city
dwellers by 2030. It is expected that 95 per cent of urban
growth in the coming decades will happen in developing
countries.
The world’s cities may only cover 3 per cent of the Earth’s
surface but they account for 60-80 per cent of energy
consumption and 75 per cent of carbon emissions. As
of 2016, 90% of city dwellers were breathing unsafe
air, resulting in 4.2 million deaths due to air pollution
annually. More than half of the urban population
worldwide was exposed to air pollution levels at least 2.5
times higher than the safety standard.
SDG 13:
Climate Action
From 1880 to 2012, average global temperatures rose by
0.85°C. To put that into perspective, grain yields fall by
about 5 per cent for every degree that the temperature
increases. Yields of maize, wheat and other major crops
decreased significantly by 40 megatons a year between
1981 and 2002 due to the warmer climate.
Oceans have warmed up, amounts of snow and ice have
gone down and sea levels have risen. From 1901 to 2010,
the global average sea level rose by 19 cm as the oceans
expanded due to warming and as ice melted. The Arctic
icecap has been shrinking every decade since 1979, with
1.07 million km2 of ice being lost per decade.
Given current concentrations and continued greenhouse
gas emissions, it is likely that global temperatures will be
more than 1.5°C higher by the end of this century than
they were in 1850 to 1900 (for all but one scenario). The
world’s oceans will warm up and the melting of ice will
continue.
The predicted average sea level rise is 24-30 cm by
2065 and 40-63 cm by 2100. Most of the aspects of
climate change will continue for many centuries even if
emissions are stopped.
Global emissions of carbon dioxide (CO2) have increased
by almost 50 per cent since 1990 and they grew faster
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etween 2000 and 2010 than in any of the previous
three decades.
It is still feasible to limit the increases in average
global temperatures to two degrees Celsius above the
pre-industrial levels if a wide range of technological
measures and behavioural changes are adopted. Major
institutional and technological changes may make
it possible to avoid global warming exceeding this
threshold.
Sources of climate change
Anthropogenic warming reached about 1°C above preindustrial
levels in 2017 and it is going up at an average
of 0.2°C per decade. Warming that is above the global
average has already been seen in many regions and
seasons, with the average warming above land being
higher than above the oceans.
Most land areas are undergoing warming at above the
global average rate, while most ocean areas are warming
more slowly. Depending on the temperature dataset
used, 20-40% of the world’s population live in regions
that experienced warming of more than 1.5°C above preindustrial
levels during at least one season in the decade
from 2006 to 2015.
Global warming rate
Current rate of warming
1.5˚C
Anthropogenic warming
2017
Climate uncertainty
for the 1.5°C graph
Observed warming
1960 1980 2000 2020 2040 2060 2080 2100
Source: UN report ‘The heat is on’
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Past emissions alone are unlikely to raise average
global temperatures to 1.5°C above pre-industrial levels,
but past emissions do cause other changes, such as
further rises in sea levels. If all anthropogenic emissions
(including those related to aerosols) were to be reduced
to zero with immediate effect, any further warming
above the 1°C already experienced would probably
remain below 0.5°C over the next two to three decades
and indeed below 0.5°C over a century, thanks to the
opposing effects of various climate processes and
factors. Warming by more than 1.5°C is therefore not
geophysically inevitable; whether it will happen depends
on future emissions reductions.
All the 1.5°C pathways involve limiting cumulative
emissions of long-lived greenhouse gases (including
carbon dioxide and nitrogen oxides), as well as
significantly reducing other substances that affect
the climate. Limiting cumulative emissions either
means reducing net global emissions of long-lived
greenhouse gases to zero before the cumulative limit
is reached, or requires net negative global emissions
(i.e. anthropogenic removal) after the limit has been
exceeded.
Sources associated with warming to 1.5°C above preindustrial
levels can be identified using a series of
assumptions about economic growth, technological
developments and lifestyles. However, the lack of
cooperation worldwide, the shortfall in political and
administrative input about the energy and land
transformations required, and increases in resourceintensive
consumption are major obstacles to achieving
the 1.5°C pathways. Available calculations aiming at
exceeding the 1.5°C target by a limited amount (less
than 0.1°C) or by zero assume 25-30 gigatons of CO2
equivalents per year for greenhouse gas emissions by
2030. This contrasts with the median estimates, which
assume 52-58 Gt CO2(eq)/year by 2030.
Pathways aimed at limiting warming to 1.5°C by 2100
(after temporarily exceeding the temperature target)
assume large-scale deployment of carbon dioxide
removal measures, which are uncertain and carry
obvious risks.
In model pathways where there is zero or limited
overshoot of the 1.5°C target, global net anthropogenic
CO2 emissions fall by about 45% from 2010 levels by
2030 and reach net zero around 2050. To achieve at
least a 66% probability of limiting global warming to
less than 2°C, most extrapolations suggest that CO2
emissions must fall by about 25% by 2030 and reach net
zero around 2070.
Limiting warming to 1.5°C requires a clear shift in
investments. Compared to pathways without new
climate policies, additional annual average energyrelated
investments for the period 2016 to 2050 in
pathways that limit warming to 1.5°C are estimated
at about $830 billion, on top of the pathways already
taken (i.e. baseline). Total energy-related investments
have to increase by about 12% in the 1.5°C pathways, as
compared to 2°C pathways. Average annual investments
in low-carbon energy technology and energy efficiency
need to be scaled up by a factor of about six by 2050
compared to 2015, overtaking fossil investments
worldwide by about 2025.
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Change in surface temperature due to cumulative CO2 emissions
Change in surface temperature from 1850-1900 (°C)
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0 1000 2000 3000 4000 5000 6000
Cumulative carbon dioxide emissions since 1876 (GtCO2)
Average historic ESMs/EMICs from AR5
Average RCP8.5 ESMs/EMICs from AR5
ESM/EMIC range from AR5
Historic warming (observed)
Historic warming (CMIP5)
GMST historic warming (observed)
16-84% TCRE range
33-67% TCRE range
average TCRE
observed averages
ESM: Earth system modelling
EMIC: ESM with Intermediate Complexity
AR5: 5 th assessment report (IPCC)
RCP8.5: representative concentration pathway
CMIP5: Coupled Model Intercomparison
Project Phase 5
GMST: Global mean surface tempeature
TCRE: transient climate response to
(cumulative carbon) emissions
Source: UN report – The heat is on
Cumulative CO2 emissions budgets
Another way of setting emission reduction targets
compared to today is based on the idea of a CO2
budget, i.e. the maximum cumulative amount of
CO2 that can be emitted into the atmosphere while
maintaining a reasonable chance of avoiding a
specified level of global warming.
Various scenarios have been determined based on
estimates for the CO2 budget in 2011:
- For a 50 per cent chance of at least achieving the
2°C target: no more than 1,300 Gt CO2(eq)
- For a 66 per cent chance of at least achieving the
2°C target: no more than 1,000 Gt CO2(eq)
- For a 50 per cent chance of at least achieving the
1.5°C target: no more than 550 Gt CO2(eq)
Cumulative CO2 emissions between 2012 and 2016 came
to about 184 Gt CO2(eq), which means that between
2012 and 2016 the world consumed one sixth, one fifth
and one third respectively of the available CO2 budget
from 2011 for a 50 per cent chance of achieving the 2°C
target, a 66 per cent chance of reaching the 2°C target,
or a 50 per cent chance of attaining the 1.5°C target.
The calculations show that the remaining CO2 budget
will be consumed quickly at current levels of emissions.
The situation is more extreme under the higherprobability
scenarios and those limiting warming to
lower levels. Once the budget for a given scenario has
been exhausted, achieving the temperature target
becomes less likely, more expensive or both. Managing
a CO2 budget sensibly means reducing emissions so
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Remaining CO2 budget for various probabilities of restricting warming
to 2°C or 1.5°C – Global warming rate
CO2 budget for a 50% probability
of restricting the temperature
increase to 2°C
CO2 budget for a 66%
probability of restricting the temperature
increase to 2°C
CO2 budget for a 50% probability
of restricting the temperature
increase to 1.5°C
Remainder Emissions from 2012-2016
Source: UN, Climate action and support trends 2019
that global carbon neutrality can be achieved before
the budget runs out. According to the data, emissions
have not yet peaked. The later the emissions peak and
start to fall, the more CO2 will have accumulated in the
atmosphere.
Cumulative CO2 emissions are kept within a budget by
reducing global annual CO2 emissions to net zero. This
analysis suggests a remaining budget of about 420 Gt
CO2 for a two-in-three chance of limiting warming to
1.5°C and of about 580 Gt CO2 for a fifty-fifty chance.
The definition of the remaining carbon budget used here
is the cumulative CO2 emissions from the beginning
of 2018 until net-zero global warming emissions are
achieved, defined as a change in air temperatures near
the surface worldwide. Staying within a remaining carbon
budget of 580 Gt CO2 means achieving CO2 neutrality
within about 30 years, or only 20 years if the remaining
CO2 budget is taken to be 420 Gt CO2.
Effects of buildings
Buildings account for 32% of global energy consumption
(IEA, 2016c) and have massive energy-saving potential
thanks to the technologies available such as energy
efficiency improvements in technical systems, in
thermal insulation (Toleikyte et al., 2018) and energy
supply (Thomas et al., 2017). Kuramochi et al., (2018)
show that the pathways to remain on track for 1.5°C
warming require an 80-90% reduction in emissions from
buildings by 2050, new buildings to be almost fossil-free
by 2020 and existing buildings to be renovated faster
at up to 5% per year in OECD countries (Organisation for
Economic Cooperation and Development).
The IEA-ETP (IEA, 2017g) identifies a large savings
potential in heating and cooling through improved
building design and more efficient equipment and lighting.
24

Several examples of zero net energy in buildings are now
available 1001 . In existing buildings, renovation can achieve
both energy savings 1002 and cost savings 1003 .
Reducing the energy in building materials further
reduces energy consumption and greenhouse gas
emissions 1004 , particularly through increased use of
sustainable materials 1005 and wooden structures 1006 .
The United Nations Environment Programme (UNEP3)
estimates that improving the energy embodied in
buildings, their thermal performance and their direct
energy can reduce emissions by 1.9 Gt CO2e/year (UNEP,
2017b), with an additional reduction of 3 Gt CO2e/year
through energy-efficient appliances and lighting (UNEP,
2017b). Further increases in the energy efficiency of
appliances and lighting, heating and cooling offer the
potential for further savings 1007 .
Recycling materials and developing a circular economy
can be institutionally challenging, in that it demands
advanced capabilities 1010 and organisational change 1011 ,
but there are benefits in terms of costs, health,
governance and the environment 1012 . No analysis of
the effects on energy consumption and environmental
problems is available, but substitution can play a key
role in reducing emissions 1013 , although its potential
depends on e.g. the demand for materials and the rate of
conversion of buildings 1014 . Substitution of materials and
CO2 storage options are being developed, e.g. using algae
and renewable energy to produce carbon fibre, that can
become a net carbon sink 1015 .
Smart technology based on the Internet of Things and
building information modelling offer opportunities to
accelerate energy efficiency improvements in buildings
and cities 1008 . Some cities in developing countries are
already using these technologies to achieve low-carbon
infrastructure, buildings and appliances 1009 .
Notes:
1001 Wells et al., 2018
1002 Semprini et al., 2017; Brambilla et al., 2018;
D’Agostino and Parker, 2018; Sun et al., 2018
1003 Toleikyte et al., 2018; Zangheri et al., 2018
1004 Cabeza et al., 2013; Oliver and Morecroft, 2014;
Koezjakov et al., 2018
1005 Lupišek et al., 2015
1006 Ramage et al., 2017
1007 Parikh and Parikh, 2016; Garg et al., 2017
1008 Moreno-Cruz and Keith, 2013; Hoy, 2016
1009 Newman et al., 2017; Teferi and Newman, 2017;
Cross-Chapter Box 13 in Section 5
1010 Henry et al., 2006
1011 Cooper-Searle et al., 2018
1012 Ali et al., 2017).
1013 Ahman et al., 2016
1014 Haas et al., 2015
1015 Arnold et al., 2018
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26

2
CLIMATE AND SUSTAINABILITY IN THE NETHERLANDS
27

EXPLORATORY STUDIES
To tackle global environmental changes and improve people’s well-being, many countries have signed
international treaties and agreements. The Netherlands has also undertaken to do this. At the request
of two ministries, the Netherlands Environmental Assessment Agency (PBL) has summarised the
core messages of five recently published worldwide environmental reviews*), focusing on tackling
climate change, land degradation and the loss of biodiversity and ecosystem functions. At the same
time, there was a search for lessons that can be learned for the transitions that the Netherlands has
embarked upon: towards a sustainable energy supply, towards closed-cycle agriculture and towards a
circular economy.
The five exploratory environmental reports present
an unambiguous message: action is urgently needed
to halt further environmental degradation and meet
internationally agreed targets. Even if existing national
plans to combat climate change are implemented in
full, the world is heading for a three-degree rise in global
temperatures, whereas the Paris Climate Agreement
stipulates a maximum of two degrees. Although there
is a global agreement to halt land degradation and
biodiversity loss, extrapolating current trends points
toward continued land-use changes (deforestation
for agriculture in particular), declining soil fertility and
further – possibly even accelerated – degradation of
nature and ecosystem functions. The negative effects
of environmental degradation are already visible and
disproportionately affecting poor communities and
vulnerable groups worldwide. Continuing on the current
path will mean that internationally agreed environmental
targets cannot be met. This puts pressure on the
realisation of the Sustainable Development Goals (SDGs)
and therefore on the welfare of current and future
generations. Moreover, it is in many cases cheaper and
less invasive to take action now rather than later on and
having to reverse further environmental damage.
Mutual interconnectedness
Climate change, land degradation and biodiversity loss
are environmental effects that are strongly interlinked.
Not only do they affect each other negatively and
derive from the same root causes, but their possible
solutions are also strongly interconnected and can
either reinforce or counteract each other. Changing
consumption patterns, using natural resources more
efficiently and restoring soils and ecosystems all help
resolve multiple environmental and socioeconomic
problems at the same time (synergy). In contrast,
climate mitigation measures that require land (e.g.
bioenergy and reforestation) and intensification
of agriculture often involve numerous trade-offs.
Large-scale production of biomass, for instance, may
conflict with protecting biodiversity and improving food
security; intensification of agriculture may go hand
in hand with increasing nitrogen surpluses and water
demand. Exploiting synergies and avoiding or reducing
trade-offs demands an integrated approach aimed
at policy integration and cohesiveness, addressing
environmental issues as an interrelated whole.
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Consumption pattern
The five exploratory environmental studies cover
a wide range of behavioural, technological and
management measures.
The size and urgency of the task mean that measures
from all three categories are needed. Changes in
consumption patterns strengthen the synergy for
achieving numerous environmental and social goals.
There is also a growing awareness that technological
solutions have their downsides. Greater emphasis on
changing consumption patterns reduces dependence on
technological solutions but also requires a major change
in the welfare paradigm of material consumption and
economic growth, particularly for the current generation
with their large environmental footprint.
Despite the policy efforts and the progress that has been
made, greenhouse gas emissions in the Netherlands
are still high, livestock farming is pushing its ecological
and social limits and biodiversity is under huge pressure.
Compared to other European countries, the Netherlands
scores very poorly. Moreover, Dutch consumers have a
relatively high (and for some indicators even increasing)
environmental footprint with a significant impact beyond
the country’s borders.
Several general lessons can be drawn from the key
insights from the five global exploratory studies for three
upcoming Dutch transitions: towards a sustainable
energy supply (Climate Agreement 2019), towards
closed-cycle farming (LNV vision 2018) and towards a
circular economy (Nationwide Programme 2016).
Perhaps the most important and at the same time
maybe the biggest challenge are consumption
patterns, such as reducing meat and dairy
consumption. Promoting behavioural change is a
challenge because it touches on people’s worldview
and their views about the quality of life. Consumption
patterns are largely determined by social routines that
cannot be changed overnight.
Ecological footprint
A large proportion of the environmental burden is caused
by the production processes used to make our consumer
goods, which is why the UN panel is calling for a change
in current ways of consuming and producing. The Dutch
cabinet’s response has been to set a target of halving
the ecological footprint of Dutch consumers by 2050.
The environmental pressures associated with
production and consumption are known as the
ecological footprint. The Dutch ecological footprint
quantifies the burden that national consumption is
placing on the raw materials available worldwide. It
covers the raw material requirements throughout the
value chain from primary production and industrial
processing to final consumption. This is the net
combined consumption of the Dutch populace,
including the consumption of governmental bodies.
The ecological footprint is expressed in ‘global
hectares’, the average amount of space needed
worldwide to produce biological raw materials for our
consumption. This includes the space that would be
needed to offset the CO2 emissions of consumption by
sequestering carbon in forests. This space is referred to
as ‘virtual’ because it is not actually occupied.
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30

Dutch consumption has an ecological footprint that
is typical of the consumption patterns of prosperous
Western countries. The ecological footprint of Dutch
consumption grew from the early eighties until around
2007, after which falling energy use meant that the
footprint began to shrink slowly. Much of the Dutch
ecological footprint consists of the land needed to
produce the food, paper and wood we consume, and
more than half of it is the area needed to compensate
for the greenhouse gas emissions due to energy used in
Dutch consumption.
that are felled to produce cattle feed on that land. The
aim of halving the footprint thus requires both national
policies for domestic consumption and production, and
international policies for the environmental effects
of production elsewhere. It should be noted that the
consumption footprint does not include raw materials
used in the Netherlands for producing food and goods
that are exported, such as milk and cheese for foreign
consumption. A proportion of the environmental impact
of production in the Netherlands therefore falls outside
the scope.
The land-use footprint of Dutch consumption in 2017
was about three times greater than the country’s land
area. After shrinking during the economic crisis of the
previous decade, it is now growing again. About 80 per
cent of this land use is outside the Netherlands. The
greenhouse gas footprint from energy consumption in
2015 was 230 megatons of CO2 equivalents. About a
third of these emissions are related to domestic energy
use, both direct emissions at the consumer’s home and
indirect emissions within the supply chains for producing
electricity and fuels. As is the case for the land footprint,
much of the greenhouse gas footprint lies outside the
Netherlands (about 40 per cent); this is related to the
production of goods and services abroad.
Sustainable Development Goals (SDGs)
Resources and raw materials are indispensable for
achieving the UN Sustainable Development Goals.
Producing, processing and using raw materials creates
environmental pressures and affects nature both on
land and in water; SDGs have been formulated for
these effects. The development goal for sustainable
consumption and production patterns aims to balance
the demand for raw materials on the one hand and limit
impacts on the environment and nature on the other.
Various footprint indicators can be used that cover the
relationships between demand and effect.
If the Dutch footprint is to be halved, the Netherlands will
also have to adopt an international trade policy. Many of
the goods and products we consume (e.g. food, energy
and raw materials such as metals) are imported. Dutch
consumption patterns therefore affect both nature in
the immediate vicinity and nature and environmental
conditions elsewhere in the world, such as the forests
31

Relationship between sustainable development
goals and footprint indicators
Human needs
Zero Hunger
Affordable and
Clean Energy
Demand for
resources
Industry, Innovation
and Infrastructure
Sustainable Cities
and Communities
Source: JRC 2019; adapted by PBL
Greenhouse gas footprint of the Netherlands
The total greenhouse gas footprint created by
consumption in the Netherlands in 2015 was 232
megatons of CO2 equivalents, i.e. almost 14 tons of CO2(eq)
per capita (Wilting et al., 2021). About a third of these
emissions are related to domestic energy consumption.
Greenhouse gas footprint of Dutch
consumption, per person
Tons of CO2 equivalents per capita
20
Responsible
consumption
and production
Footprint indicators
Use of resources
Ecological footprint
Materials
Water
Environmental
burdens
Greenhouse gases
Nitrogen oxide
Phosphates Impact
Particulate matter
Ozone
Land use
Effects
Biodiversity
Eutrophication
Ecosystem services
Impact
pbl.nl
Natural capital
Clean Water and Sanitation
Climate Action
Life Below Water
Life On Land
This includes both direct emissions that occur at the
consumer’s location such as heating and driving,
and indirect emissions in the chain for producing the
electricity and fuel consumed. Services (including trade
and transport) contributed almost 40 per cent of the
greenhouse gas footprint in 2015. A large proportion
of the greenhouse gas footprint also lies outside the
Netherlands (about 40 per cent) due to association
with the locations where products and services for the
Netherlands are made. The trend in the Netherlands’
greenhouse gas footprint shows a steady downward
trend over the period 2007 to 2015, albeit with some
fluctuations. More recent trends (through to 2020) are
not yet known, as international databases for calculating
the foreign component are not yet available.
Reducing the footprints
Options for intervening in the production and
consumption chain will differ in terms of how much they
can help reduce footprints and meet biodiversity targets.
Energy consumption by consumers (or more generally,
the energy consumption of buildings) can for instance be
reduced by insulation. The need for primary raw materials
can be cut by circular reuse strategies: not only recycling
products or reusing waste but also sharing products and
reusing and redesigning them.
15
10
5
0
2005 2007
2009 2011 2013 2015
Energy in the chain
Energy for households
Other services
Trade and transport services
Other goods
Food
pbl.nl
Relevance for the solar shading industry
For this sector, consumption patterns may seem a bit
more abstract. There are, however, points of interest that
are much closer to home: climate and energy, as well as
the circular economy.
Source: PBL
32

For climate and energy, there is a direct contribution
by sun awnings as a product: applying dynamic sun
shading can reduce energy consumption in buildings and
simultaneously help cut emissions of greenhouse gases.
The challenge for the sector is to present the narrative
correctly, to provide the evidence in building-specific
situations and to show that the entire value chain is (on
balance) less environmentally harmful than the gains
over the technical lifespans of the final systems.
Together with DGMR, Somfy Nederland has developed
a model that makes it possible to mimic energy
consumption in a room; specifically, an office was
used for the model. Based on that, it was possible to
extrapolate the results to an entire office building.
Office buildings are currently the priority, but it seems
obvious to use the method for other types of buildings
as well. In fact, the method makes it possible to give
real-world answers to two questions, namely the
energy consumption reduction achieved using dynamic
shading in an office building, and the related reduction
in CO2 emissions. This lets us help resolve the first
two challenges described earlier in this section. The
third point mentioned has already been the subject of
research in Germany (see The Somfy Factor, first edition
p. 69) and remains unanswered here. The goal of a
fully circular economy by 2050 and the intermediate
objective of halving the use of primary abiotic raw
materials by 2030 need to be made more concrete.
For the intermediate objective, this concretisation
includes the question of whether it also applies to
fossil fuels, adopting a chain approach to give a
clear picture of overall consumption of raw materials
(including environmental burdens beyond the country’s
borders), and utilising both production and consumption
perspectives (as both offer relevant handles for setting
policy). Current steering mechanisms that focus on
the input of raw materials do not per se help lower
environmental burdens and make supplies more secure,
whereas they are the ultimate goals of the transition to a
circular economy.
In that respect, the sun awnings industry still has some
way to go. The initiative will have to come from major
manufacturers who have the knowledge and resources
to create a full picture of that aspect of their processes
and determine how circular their products are. There will
hopefully be a readiness to improve once the baseline
has been determined. Although we do not yet know the
facts, it seems safe to assume that improvements can
be made.
Awareness (and raising the awareness level) are more
effective and faster than waiting for new legislation,
which can take years. Improvements can be accelerated
by informing consumers better about this topic. This
applies market pressure on producers, driving innovation
and bringing opportunities to add value in the supply
chain, as well as giving producers a chance to stand out
from the crowd.
* For the sake of completeness, here are the five exploratory studies in question: Global Land Outlook: first edition (UNCCD, 2017), Global Warming of 1.5°C (2018, IPCC), Global Environment
Outlook 6: Healthy Planet, Healthy People (2019, UNEP), Global Resources Outlook 2019: Resources for the future we want (2019, IRP) and The Global Assessment Report on Biodiversity
and Ecosystem Services (2019, IPBES).
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36

3CLIMATE LEGISLATION
37

GLOBAL WARMING
The Earth is getting warmer as a result of the huge quantities of greenhouse gases entering the
atmosphere. The chief culprits are methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2).
Although these gases do belong in the atmosphere, their concentrations have gone up massively
over the last 150 years because of human activity. These gases are collectively referred to as
‘greenhouse gases’. It should be noted that without the basic concentrations of these gases, the
average temperature on Earth would be -18 degrees Celsius. They retain the sun’s heat in the
atmosphere. However, elevated concentrations increase this effect with a variety of consequences
such as higher temperatures, rising sea levels and disrupted ocean circulation patterns.
We can now consider global warming to be a fact.
Estimates of the effects on the average temperature
vary. According to calculations by the UN, the difference
between a 1.5-degree and a 2-degree rise boils down to
2.6 times more extreme heat, 10 times more summers
without ice at the North Pole, 2.3 times more crop
failures, occasional devastating floods, devastating
forest fires like those in Australia and California, and
50% less fertile farmland.
We can’t get round it: Man is the biggest polluter. The
main cause is fossil fuels such as oil, coal, lignite and
natural gas. Fossil fuels are pumping CO2, formed from
the remains of plants and animals that had been stored
in the Earth’s crust for over 300 million years, back into
the atmosphere. More than half of all anthropogenic
CO2 emissions have been over the last 30 years. It’s no
wonder that the planet is protesting!
Rising sea levels
At the end of 2019, scientists announced in a
publication in Nature that the ice cap in Greenland is
melting 4 times faster than in the twentieth century.
Many people will remember the TV images from
the summer of 2020 of swirling masses of water in
Greenland as a result of a heat wave with temperatures
rising to 20 degrees Celsius.
If melting continues at this pace, sea levels will have
risen 67 centimetres (!) by the end of this century. The
knowledge institute Deltares has calculated that the
sea level off the Dutch coast rose by an average of 1.86
millimetres per year over the past century, a rate that
is currently not accelerating. The rise off the coast here
is therefore lagging behind the average, partly because
the meltwater from Greenland has not reached the
area (yet).
The estimates of global warming doing the rounds in
political circles are long outdated. Climate scientists
at the University of Wyoming are now working with
models in which warming is accelerating over time. It is
probably more realistic to multiply the numbers that are
currently circulating by a factor of two.
Other countries may be affected earlier and will sooner
or later face existential choices: letting land flood or
carrying out massive infrastructure projects. Islands
like Fiji and the Maldives may fear for their very survival
with these rises in sea level. These countries will
just literally disappear into the ocean if no swift and
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39

appropriate response is forthcoming. In the long run, of
course, this is just as true for the Netherlands.
Elon Musk, by the way, has come up with a revolutionary
solution for this. He suggests digging up the seabed
with giant excavators and using the material obtained
for raising the Earth’s surface. Some scientists are
calling it Musk’s most realistic plan yet...
Climate mitigation
Preventing further climate change by reducing
greenhouse gas emissions is called climate mitigation.
This works best when countries work together, so that
has to be done at government level.
The Netherlands has committed itself to several
international agreements. The key ones are:
- The 1992 United Nations Climate Convention; this
was the first such treaty.
- The 1997 Kyoto Protocol, which states that
emission reductions will vary from country to
country and can be traded between them.
- The UN climate summit in Paris (the Conference
of Parties – COP21) in 2016, at which the
Netherlands agreed to a new UN climate
agreement aiming to limit global warming to well
below 2 degrees Celsius, with a clear route to 1.5
degrees Celsius.
The UN Paris Climate Agreement
The 2016 Climate Agreement came into force in 2020.
It was signed by the (then 28 ) EU member states and
aims to reduce the EU’s greenhouse gas emissions
by at least 40% by 2030. The European Commission
checks the climate plans of the EU member states
against the targets set.
European Green Deal
Climate change and environmental degradation are
putting the future of Europe and indeed the world at
risk. In response, the European Commission drew up the
European Green Deal, an approach for transforming the
EU into a modern, resource-efficient and competitive
economy, with the primary goals of:
- net-zero greenhouse gas emissions by 2050
- economic growth without exhausting resources
- no person or region left to fend for themselves
The European Green Deal provides the blueprint for this
dramatic transformation. All 27 EU member states are
determined to make the EU the first climate-neutral
continent by 2050 and they have therefore committed
to reducing emissions by at least 55% (with respect to
1990) by the end of 2030.
The Green Deal is being financed with one third of the
1.8 trillion euros for the NextGeneration EU recovery
plan and from the EU’s seven-year budget.
40

Despite its name, the ‘deal’ is not a signed agreement
but in fact an initial legislative proposal for making
the EU climate-neutral by 2050. It is possible that the
Green Deal will give Europe an opportunity to present
itself as one of the world’s leaders and let Europe show
China and the USA the way forward – and in so doing
perhaps become top dog again economically and
technologically, ahead of China and the USA.
Some key elements of the European Green Deal, which
contains a total of fifty climate-related actions, are:
- An end to fossil fuel subsidies. According to an
OECD estimate, €39 billion per year is spent on
this in the EU.
- A fund will be set up to provide financial
assistance to the countries most affected by the
energy transition as envisaged.
- As the energy sector is responsible for 75% of
greenhouse gas emissions, its use of fossil
fuels will be phased out. There will be funds for
developing renewable energy.
- The price of polluting transport will become a fair
reflection of the emissions. Tax exemptions for
air and sea transport will be reconsidered.
- There will be sustainability standards for
European food, a plan to make food supplies
more sustainable and a plan for making industry
cleaner and more circular.
As is well known, the United States withdrew from the
Climate Agreement under Trump, while Biden rejoined
it. As far as China is concerned, the economic situation
means that the country has currently adopted a waitand-see
attitude.
The European Green Deal also incidentally left open
the possibility of implementing a CO2 tax for products
originating from countries that do not tighten up their
climate policies; this is naturally intended to protect
European competitive positions, while at the same time
providing an incentive for such countries to do so. It will
surprise nobody to learn that China is not in favour of this.
Calculations show that the current package of
measures, applied by all countries combined, will still
leave average temperatures on Earth rising by more
than three degrees compared to the period before the
Industrial Revolution; this is twice the limit that was at
one time stated as being needed to prevent dangerous
climate changes. In the meantime, investment in fossil
fuels continues at a high level (estimated at $1.9 trillion
since 2015).
Apparently, trees are in again in Europe. Frans
Timmermans, the European Commission's Executive
Vice-President for the European Green Deal, has set
his sights on an additional 2 billion trees in the EU,
the same figure that Jeremy Corbyn mentioned for
the UK alone over the next 20 years. That’s quite a lot:
it means 3 new trees every second, 24 hours every
day. Both of them realise that trees take CO2 out of the
air, which helps in Europe’s race to achieve climate
neutrality by 2050.
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43

Madrid Climate Summit
The outcome of the Madrid Climate Summit did not
really satisfy anyone. China and the United States
were at least talking, albeit reluctantly – and they are
the world’s two worst polluters. The emission rights
system has not turned out to be workable in practice.
Another tricky issue is how poorer countries should be
compensated for the costs of the transition.
Netherlands: Climate Agreement
On 28 June 2019, the Dutch Cabinet presented the
Climate Agreement and started implementing it. The
agreement contains more than 600 commitments to
reducing greenhouse gas emissions, mainly under the
aegis of the ministries of Economic Affairs and Climate
Policy (electricity and industry), the Interior (built
environment), Agriculture, Nature and Food Quality
(agriculture and land use) and Infrastructure and Water
Management (mobility).
The key points of the Climate Agreement:
- Three hundred of the worst polluter companies
will pay a national carbon tax on emissions that
must also be reduced to meet the climate targets
by 2030, while subsidies for sequestration and
underground storage of CO2 will be limited.
- The coal-fired power station at Amsterdam
Hemweg has closed by now, the Maasvlakte
coal-fired power station will close or switch to
biomass by 2030, and the same will also apply
to the Geertruidenberg power station. By 2030,
more than 70% of electricity production must
come from renewable energy sources.
- Gas will become more expensive and electricity
cheaper. There will be a heating fund for private
individuals worth €50-80 million a year, through
which members of the public can take out loans
on favourable terms for purchasing heat pumps,
for example. On top of that, the government is
starting a subsidy scheme to the tune of €100
million per year for investments in insulation and
heating systems. By 2021, all municipalities also
have to announce which districts will be taken off
the gas supplies and when.
- Major changes are also taking place in the
mobility domain, with road use pricing once
again being tabled as an option. From 2030
onwards, all new vehicles sold will be expected to
be electric. At the same time, the excise duty on
diesel will be going up. The road tax for vans will
go up in several steps between 2021 and 2024.
- Money will be made available for greenhouse
horticulture businesses to let them become more
sustainable and for farmers in peatland areas to
let them stop or relocate their operations. Cash
will also be made available for owners of pig
farms who are prepared to stop.
44

There will be legislation to make construction and
buildings more sustainable, and a knowledge and
innovation platform will be created for making social
properties more sustainable.
In the meantime, numerous organisations, companies
and umbrella institutions – including the financial
sector (banks, pension funds, insurers and asset
managers) – are committed to the Climate Agreement.
The Climate Act in the Netherlands (2019)
The Climate Act defines the percentage reductions in
CO2 emissions that the country needs, thereby aiming to
clarify the climate objectives. The climate objectives are:
- 49% less CO2 emitted by 2030 (with respect to
1990). To achieve that goal, the governmental
authorities, companies and civil society
organisations have signed a Climate Agreement
that also contains agreements between
the parties.
- 95% less CO2 emitted by 2050 (with respect
to 1990).
Additionally, the Dutch state must be emitting at least
25% less greenhouse gases by the end of 2020 than in
1990. This was decided in court in 2015 in the climate
case brought by Urgenda against the Dutch state. In
the appeal in 2018 and the application to have the
judgment quashed in 2019, the court also upheld the
verdict. The ruling thereby became irrevocable.
Climate Act, Climate Plan, Climate and
Energy Exploratory Study
In addition to the goals, the Climate Act also stipulates
that the government must draw up a Climate Plan.
The first Climate Plan covers the period 2021-2030
and includes the main outlines of the policy through
which the government intends to meet the objectives
of the Climate Act. It also contains several further
considerations, for example on the latest scientific
understandings about climate change and on the
economic consequences of the policy.
One aspect that also needs to be seen in the Climate
Plan is the impact that the government’s climate policy
will have on the financial positions of households,
businesses and governmental authorities, on
employment (including education and training of
staff), on how the economy will develop, on achieving
a fair and affordable transition, and on the reliability of
energy supplies.
Progress on the implementation will be reported upon
biannually and measures will be taken, if there is reason
to do so in the light of the aims of the Act. Once a year,
the Netherlands Environmental Assessment Agency
(PBL) will publish a Climate and Energy forecast for the
Minister of Economic Affairs and Climate Policy. The
Climate and Energy exploratory report is a scientific
report looking at the consequences of climate policy as
conducted in the previous calendar year.
Annually, on the fourth Thursday of October, the Minister
of Economic Affairs and Climate Policy sends the
Climate Memorandum to both houses of parliament.
The Climate Memorandum contains inter alia the overall
picture of progress of the climate policy as stated in
the Climate Plan; the consequences of climate policy
for departmental budgets; financial consequences of
45

significant developments in climate policy that deviate
from the Climate Plan for households, businesses and
governmental authorities, plus reports on the progress
of the implementation of the Climate Plan.
The cabinet announced on Budget Day in 2021 that
it would be spending €6.8 billion extra on climate
measures. These include e.g. cutting greenhouse
gas emissions and subsidies for making homes and
infrastructure more sustainable.
An independent advisory committee led by the former
ombudsman Alex Brenninkmeijer studied in 2021 how
the public could be involved better in climate policy.
This was done at the request of the Rutte III cabinet.
The study yielded the ‘Involved with the Climate’
advisory report.
One of the report's key conclusions is that there has
only been limited systematic research into utilising
various forms of public involvement in climate policy,
which means that there is no overview. However, such
a study would be desirable and could be carried out in a
follow-up to this recommendation. Another conclusion
is that a great deal is happening in terms of public
participation and that there are instructive examples
available that can provide insights. This empirical
material provides an opportunity for more systematic
forms of research and monitoring.
46

Green Deal approach
The government launched a ‘Green Deal approach’ as
far back as 2011, intended as an interactive method
for the government to give innovative, sustainable
initiatives from society the space they need. This is
being done by eliminating bottlenecks in legislation
and regulations, creating new markets, providing good
information and ensuring optimal partnerships. Clear
bilateral agreements make it possible for participants
to work towards real-world results, with each of those
involved taking their own responsibility.
This way of working, which is still fairly new, creates the
requisite win-win situations. Not only the government
can benefit from this: companies can also benefit by
developing sustainable ideas into better competitive
positions and greater export opportunities. The
developments and innovations resulting from the Green
Deal approach can therefore significantly boost green
economic growth. Meanwhile, more than 200 Green
Deals have been concluded with more than 1,300
parties since the beginning of 2019.
The main principle of the Green Deal approach is to
ensure that there are spinoffs, as successful deals
should inspire many others in society to follow that
lead. The driving force behind the transition should be
society itself. It is thought that this approach can build
a strong economy for future generations, letting us
reduce environmental burdens and work towards an
equilibrium for nature and the living environment.
47

Sustainable construction
Sustainable homes are better for the environment than
traditional construction. Sustainable construction work
saves resources, sustainable buildings are more energyefficient,
and they are often healthier for their occupants
and residents. Respect for people and the environment is
paramount in the development of buildings. Sustainable
construction is not merely about low energy consumption
but also covers using sustainable materials that take
account of the environment and the health of occupants
and residents; a healthy indoor environment, e.g. thanks to
good ventilation; pleasant and liveable houses, buildings,
districts and cities; sustainable demolition so that materials
recovered during demolition can be reused (recycling);
responsible water use; and avoiding the depletion of raw
material resources for building materials.
The construction and use of housing and other
buildings are subject to building regulations. The
2012 Building Decree lists the technical building
requirements that buildings must comply with as a
minimum. These are regulations about safety, health,
usability, energy efficiency and the environment.
There are various approaches, visions, steps or
guidelines that can be adopted when designing
sustainable homes and buildings. The best-known
approach, which is still in use, is the Trias Energetica.
If only the construction costs (for land and building) are
considered, sustainable building can seem more expensive.
The maintenance costs of a sustainable building are often
much lower, though. The measures for saving energy and
water are paid back during the usage phase of the house,
resulting in lower energy and water bills – a plus-point for
the buyers or users of a home or building.
Central government encourages sustainable building in
construction education curricula at the lower and higher
vocational levels, as well as academic. Those students
will soon become builders, contractors or architects.
The earlier they come across sustainable construction,
the more naturally it will become for them to use such
methods in their work.
That is why the national government commissioned
the publication entitled (in translation) ‘Basisdoc:
XS 2 sustainable building’. It is an aid for learning
objectives and classroom material for sustainable
building and sustainable urban planning, covering
topics such as energy, materials, drinking water, the
indoor environment and health, as well as the living
environment. Sustainable building encourages new
products. Consider water-based and high-solid paints
that contain less harmful substances, for instance,
or energy-efficient boilers and ventilation systems,
heat pumps, solar boilers and solar panels. The
sector developed these energy-saving devices when
legislation about the energy performance of buildings
(EPG) came into force.
Sustainable refurbishment
Demand for good homes and other buildings is
continuing to grow and new construction alone will
not meet the demand. Renovating buildings raises
the quality levels and makes them comfortable again.
Renovation is often more sustainable, cheaper and
less damaging to the environment than demolition
48

followed by new construction. Extending the lifespans
of buildings is a very effective form of sustainable
construction. Renovation often saves a lot of materials
and the costs for new roads and sewers, for example,
as well as avoiding construction and demolition waste.
sustainable urban development, describing six
examples of old neighbourhoods where renewal was
chosen instead of demolition.
Transforming unoccupied office buildings into homes,
for example, is often more sustainable than demolition.
At the same time, renovating houses presents an
excellent opportunity for making them more energyefficient
and healthier.
Parts of the building are retained and less material is
needed for the renovation than if the houses were built
from scratch.
In a study by the Netherlands Enterprise Agency
entitled Kiezen voor nieuwbouw of het verbeteren
van het huidige kantoor (Choosing new construction
or improving current offices), the pros and cons of
renovation are compared against those of demolition
and new construction using five scenarios. The
document called Renovatieconcepten en bouwstenen
(Renovation Concepts and Building Blocks) gives an
overview of the various ways to renovate.
The publication Verbeteren in plaats van slopen
(Improvements instead of demolition) is about
The Ministry of the Interior and Kingdom Relations has
investigated what does not go so well when converting
offices into homes. The results are contained in a
research report entitled Transformatie kantoren gaat
niet vanzelf (Transforming offices doesn’t just happen).
Some 40,000 upper storeys above shops are estimated
to be vacant in the Netherlands, the equivalent of
about 1,500 hectares of new construction. These
empty storeys represent wasted space and buildings
that are empty after the shops’ closing time add to the
49

unsafe atmosphere in inner cities. The municipality
of Hoorn has for example made money available
through an incentive scheme for creating residential
accommodation above shops. The brochure called
Wonen boven winkels (Living above shops) shows how
other municipalities have tackled vacant premises.
Subsidies
Central government has therefore adopted various
schemes for backing sustainable construction. A few
examples are:
- Green Projects Scheme: tax breaks for
investments in recognised sustainable projects;
- NESK: for energy-neutral schools and offices;
- MIA: tax benefits for sustainable business
investments.
There are also various grants from municipalities
and provinces.
Renovation work can be a reason to take energy-saving
measures such as double glazing, cavity wall insulation
or a heat pump. There are some cases where subsidy
schemes have been set up for the purpose.
Connections to the gas network will no longer be
standard in new housing estates. The government wants
to replace the entitlement to gas connections with a
right to heating. As a result, the energy performance
requirements for new buildings are being tightened up.
Existing homes will also have to be made more sustainable.
This will be done step by step. The governmental authorities
are also making agreements with municipalities,
provinces, water boards and grid managers to make the
built environment more sustainable.
Building rules and regulations
Principals in the construction industry must comply
with the following legislation and regulations:
- Housing Act
This law is the basis for the building and usage
regulations in the 2012 Building Decree and its
regulations (the Implementing Act).
- 2012 Building Decree
This decree contains regulations about the
construction and renovation of buildings, on the
condition and use of buildings, open premises
and areas, and about demolition and safety
during construction and demolition.
- Implementing Act for the Building Decree of 2012
These regulations include requirements for CE
markings and the connection of gas, electricity
and water.
- Environmental Licensing (General Provisions)
Act (WABO)
This law bundles the requests for various
planning permissions together into one single
environmental permit.
- Environmental Law Decree (BOR)
This decree defines further detail of the WABO
regulations, such as the permit requirements and
the designation of the competent authority, as well
as the regulations for construction without permits.
- Ministerial order on environmental and planning law
These regulations state which documents
(e.g. construction blueprint) and data (e.g.
strength calculations) are required with the
50

permit application (known as the ‘submission
requirements’).
The Dutch regulations may also have to cover the
European rules. This is for example the case with
construction products, which have to be tested and
assessed in the same way throughout Europe. There
is also a directive about the energy performance of
buildings. This will ensure that the energy performance
of buildings in the European Union improves.
Municipalities enforce building regulations by ensuring
compliance with the rules, from the permit application
through to handover of the completed building.
Policy for this is laid down by the municipality in an
enforcement plan. Since 1 October 2012, the provinces
have monitored the municipalities.
Building Decree 2012
A building must not present hazards to residents,
users or the environment. The government therefore
laid down regulations for safety, health, usability,
energy efficiency and the environment in the 2012
Building Decree. The decree is a building code that
applies to construction both with and without planning
permission. There is also an Implementing Act for the
2012 Building Decree. To meet the requirements of the
2012 Building Decree, various tools such as calculation
methods, checklists and guidelines are available.
An overview:
- The NEN standards contain rules and calculation
methods to determine whether regulations under
the Building Decree are being complied with.
- There are recognised quality marks stating
whether the building material or building element
complies with the requirements of the Building
Decree.
- Provisions for equivalent solutions so that the
Building Decree can be complied with, creating
the option of deviating from the performance
required by the decree as long as the
requirement’s functional purpose is met.
- Practical guidelines for the Netherlands (NPRs)
with instructions for checking if the minimum
requirements of the Building Decree have been
met.
- Technical agreements for the Netherlands (NTAs),
also simply known as ‘guidelines’, dealing with
practical details of norms based on the Building
Decree.
The 2012 Building Decree has been amended several
times in the meantime:
- As of 1 January 2018, environmental
performance norms have applied to the
construction of new homes and business
premises of 100 m2 or more. As well as rules
for the energy efficiency of buildings, a limit
has been placed on the environmental impact
of the use of materials in construction. The
environmental burden calculation covers the
entire lifecycle of a product, from mining raw
materials through production and transport
to the use and demolition of the structure.
Recycling and reuse are also counted. See also
the information sheet called (in translation)
‘Introducing the limiting value’.
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52

53

- Since 1 July 2016, owners of indoor swimming
pools have been obliged to prove that there is no
longer any hazardous stainless steel present. The
chlorinated air at swimming pools can weaken
stainless steel. To avoid danger to visitors, the
owner must remove or replace the metal.
Advances in the understandings for buildings
Residential construction
We are facing ever-hotter summers, increasing the
need to take measures against buildings overheating.
New homes are built to be as energy-efficient as
possible and therefore retain more of their heat.
This can be an issue in the summer, with higher
indoor temperatures creating health risks as well
as discomfort. Retro-fitting inefficient portable air
conditioning to keep indoor temperatures at acceptable
levels runs counter to the policy of saving as much
energy as possible. Overheating can be prevented as
much as possible by carefully considering the design of
a building. There are various options for this.
One possibility is making sure that there are blinds
when a new house is delivered, that the ventilation
within homes has been properly thought out and/or
that the orientation of the home to the sun has been
taken into account. The new overheating requirements
came into effect on 1 July 2020 at the same time
as the requirements for nearly energy-neutral
construction (‘BENG’ in Dutch). Kajsa Ollongren, then
Minister of the Interior and Kingdom Relations, thereby
obliged the building sector to reduce the risk of the
home overheating.
The Netherlands Enterprise Agency (RVO)
commissioned W/E Consultants to study the criterion
and limit value for cutting down the risk of overheating
in newly built houses. That study resulted in the report
entitled “Limit values in the Building Decree for summer
comfort in new housing”. Based on that, RVO advised
the Ministry of the Interior and Kingdom Relations
to include the July temperature overshoot indicator
– TOjuli – in the building regulations (Advice on the
requirement to reduce risks of overheating in newly built
houses in the Environmental Regulations).
A limit value for TOjuli for new-build houses will be
included in the building regulations. This is an indicative
figure that gives a picture of the risk of the temperature
being exceeded depending on the orientation of
the building. The TOjuli is derived from the energy
performance calculation according to NTA8800. The
limit value is set at a maximum value of 1.0.
A temperature excess calculation using a dynamic
simulation programme can give a more specific
prediction of the risk of the temperature being
exceeded. If TOjuli exceeds the limit value of 1.0,
a dynamic simulation programme may be used
to demonstrate that the risk of overheating still
remains acceptable.
The limit value for the weighted temperature
exceedance, according to established calculation
principles, has been set at 450 hours. These principles
will be included in the building regulations and
detailed further.
54

Utility construction
The website of the Netherlands Enterprise Agency (RVO)
has important instructions about applying automatic
external blinds in non-residential buildings.
A comfortable indoor climate is a key principle for
selecting climate control systems in any building.
This has implications for the cooling of a building.
Sustainable cooling systems allow a comfortable indoor
climate to be achieved for low energy consumption.
More and more sustainable cooling technology is
becoming available for buildings, such as chillers with
natural refrigerants, systems that extract cold from the
environment (soil, air or water) and diabatic* cooling.
* Dewpoint cooling, also known as diabatic cooling, is a new technique for cooling
buildings such as sports halls and smaller office buildings. It is an energy-efficient and
environmentally friendly form of technology that uses water as a cooling medium.
The first step towards saving energy, however, is cutting
down the demand for cooling, for instance by insulating
the building properly. To prevent it from becoming too
hot inside the building, measures are needed such as the
use of overhangs, adjustable sunshades on the outside
of the building and making the most of shade from trees
and bushes. Good sun protection awnings are most
effective if they can be controlled automatically.
BENG requirements
Since 1 January 2013, the regulations of the 2012
Building Decree have applied when calculating the
environmental performance of buildings. At the end of
2020, the Netherlands stopped using the EPC method
(Energy Performance Coefficient) and switched to a
new method for quantifying and checking the energy
performance of buildings. It was high time too, given
that the EPG legislation dated back to 1994. In the EPC
calculations, the proportion of energy gained through
the glass was lower than the proportion of energy lost
through the glass. In the meantime, however, thermal
yields from the sun have become much more significant.
Until the end of 2020, the energy performance of
buildings was determined as per NEN 7120:2011 in
order to demonstrate that new buildings complied with
legislation on the energy performance of buildings (EPG).
Stricter requirements have applied to new buildings since
1 January 2021, known as the BENG requirements.
From 1 January 2021 onwards, new buildings have
had to meet more stringent requirements for energy
use: the ‘BENG’ requirements for nearly energy-neutral
construction. The new requirements form part of the
2012 Building Decree as of 1 January 2021, ensuring that
new buildings are more energy-efficient. The energy
performance of buildings is determined by a Technical
Agreement for the Netherlands, known as NTA 8800.
Glass surfaces nowadays provide a net annual energy
gain, with the gains from the glass area exceeding the
losses. This is one reason why buildings are increasingly
being “designed for the sun”, letting them make use of
‘free’ passive solar energy.
The BENG standard takes this into account to a
greater extent, giving a better assessment for glass.
Requirements imposed by the EU (Energy Performance
of Buildings Directive, EPBD 2016) therefore assume
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56

that as little heat as possible is lost, in line with Step 1
of the Trias Energetica for reducing energy demand.
The Building Decree contains limit values for the TOjuli
indicator within such calculation zones.
The energy performance for BENG is determined on the
basis of three independently attainable requirements,
namely the maximum energy requirement in kWh per
m2 of usable area per year (kWh/m2·yr, BENG 1), the
maximum primary fossil energy consumption, also in
kWh per m2 of usable area per year (kWh/m2·yr, BENG
2) and the minimum renewable energy proportion as a
percentage (%, BENG 3).
Utility construction:
One major concern is the risk of overheating. It can be
prevented by using overhangs, for instance, or summer
night ventilation and external blinds. It is important
to consider the way the design and the energy
performance fit together by making energy calculations
from the very first sketch. In the design stage, it is often
implicitly stated which options will be available later.
Residential construction:
Instead of expressing the energy performance
requirements as an EPC value, the new BENG indicators
apply (Bijna Energieneutrale Gebouwen = nearly
energy-neutral construction). The BENG indicators are
determined using the newly developed NTA 8800 norm,
which has replaced NEN 7120 as the determination
method. A newly developed NTA 8800 validation tool is
used for calculating the BENG indicators.
To give market parties a clear picture of the consequences
of the new quantification method and the
new BENG requirements, sample concepts have been
developed and calculated on instructions from the RVO.
The examples provide an understanding of the packages
of measures that housing can use to meet the BENG
requirements. In addition to the BENG requirements, the
houses were also checked for compliance with the TOjuli
requirement. The TOjuli indicator shows whether there is
a risk of overheating in the homes. Checks against this
requirement are only needed for calculation zones where
no active cooling system is present.
Good thermal insulation of the basic shell, fitting
triple glazing and good airtightness are decisive
factors in reducing the heat demand. In that context,
it is important to take account of both the cooling
demand in summer and the heat gain in winter to get
the optimum distribution of the percentage of glass in
non-residential buildings. This may mean less glass
surface on the south-facing side to minimise the
cooling capacity needed to meet comfort requirements
in the summer. Dynamic solar shading is therefore
increasingly being used in non-residential buildings.
The BENG requirements are different for every type
of building. The European EPBD directive states that
government buildings have a role-model function and
that new government buildings must therefore be nearly
energy-neutral from 1 January 2019 onwards when an
environmental and planning permit is applied for.
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Energy performance calculations and
energy labels for residential buildings
When applying for environmental planning permission
and upon handover of a new residential building, the
BENG requirements must be verified at the building
level (each premises ID). In addition, the energy
performance must also be calculated and recorded for
each individual accommodation unit (e.g. the individual
flats in a residential building). This is needed so that the
energy performance will be made known in time to the
potential buyers and users. This also gives a picture of
the risk of overheating for each accommodation unit.
The risk of excessively high temperatures is determined
for residential premises for each calculation zone
and for each orientation (the TOjuli indicator, which
is given automatically by the drafting software). The
TOjuli requirement test for new dwellings is only needed
for calculation zones where there is no active cooling
system. The Building Decree contains limit values
for the TOjuli indicator within such calculation zones.
Calculation zones where no active cooling system has
been installed have to comply with this criterion.
When registering the energy performance for residential
premises for permit application purposes, an energy
label is issued with a 'provisional’ status. When
delivered, each individual residential building must
have a registered energy performance report (an energy
label). The energy performance is recorded on site for
that purpose. An energy label with the status 'final’ is
then issued for the energy performance as recorded.
European Energy Performance
of Buildings Directive
The European Energy Performance of Buildings
Directive states that all new buildings must be nearly
energy-neutral. In short, that boils down to:
- The directive promotes improvement of the
energy performance of buildings, taking account
of not only the climatic and local conditions
outside the building but also the requirements for
the indoor climate and cost-efficiency.
- The directive sets out rules for (a) the general,
common framework for a methodology for
calculating the integral energy performance
of buildings and building units; (b) applying
minimum requirements to the energy
performance of new buildings and new building
units; (c) applying minimum requirements to
the energy performance of (i) existing buildings,
building units and building elements undergoing
major renovations; (ii) building elements that are
part of the building shell that after having been
renovated or replaced will have a significant
impact on the energy performance of the building
shell; and (iii) technical systems in the building
when they are installed, replaced or upgraded;
- National plans must provide for an increase in
the number of nearly energy-neutral buildings,
the energy certification of buildings or building
units, regular inspection of heating and airconditioning
systems in buildings, independent
systems for verifying energy performance
certificates and inspection reports;
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- The directive’s requirements are minimum
requirements and do not prevent a member
state from enforcing or introducing more
stringent measures. Such measures must be
compatible with the Treaty on the Functioning
of the European Union and must be notified to
the Commission.
transport) and for the Environmental Accounts as well
as the environmental module of the National Accounts.
To be able to implement international policy for tackling
the enhanced greenhouse effect, the Intergovernmental
Panel on Climate Change (IPCC) has drawn up a
regulation (IPCC, 2006 and its revisions) that every
country must use as the basis of its reporting. The
emissions reported this way can be compared across
countries or added up to give a global figure (Olivier
et al., 2002). Emissions of short-cyclic CO2 are not
included in the overview of actual emissions because
these are not deemed to be a net contributor to the
greenhouse effect.
The IPCC figure is also used for working out the
reduction that can be achieved. The ‘bunker emissions’
are also requested by the IPCC as a separate figure.
Bunker emissions are the emissions from kerosene
and fuels used by international shipping that are sold
in the Netherlands.
The Environmental Accounts are based on the National
Accounts issued by Statistics Netherlands. These cover
emissions caused by the activities of Dutch residents.
Emission values
Actual emissions for the Netherlands means the CO2
emissions on Dutch territory. The emission value
comprises several basic elements (stationary sources,
short-cycle CO2 and mobile sources). These emissions
can be found at www.emissieregistratie.nl. They are
used as input for model calculations (concentrations;
The IPCC figure is also used for working out the
reduction that can be achieved. The Netherlands is
aiming to achieve a reduction of 55% by 2030 and 95%
by 2050 (compared to 1990).
Climate legislation is slowly but surely infiltrating all
sorts of sectors; it is therefore increasingly going to
affect both private individuals and companies.
59

Financial sector
Roughly fifty banks, insurers, pension funds and asset
managers plus their various umbrella organisations
signed up to the government’s climate targets on 10
July 2019, undertaking to report on the climate impact
of their financing and investments from 2020 onwards.
Moreover, they were to have action plans ready by 2022
that will help reduce CO2 emissions.
institutions, including Invest-NL, to increase the funding
options for climate-friendly projects.
As set forth in the undertaking, the four financial
umbrella organisations (the Dutch Banking Association,
the Dutch Association of Insurers, the Federation of the
Dutch Pension Funds and Dufas, the Dutch Fund and
Asset Management Association) are organising working
conferences on measuring and targeting climate
impact. The Sustainable Finance Platform is involved
in this. The aim is to share knowledge and experiences.
This refers to knowledge about both the funding of
sustainability projects and measuring the CO2 footprint
of financing and investments.
The sector is therefore helping both nationally and internationally
to achieve the Paris climate goals. The undertakings
are not without obligations. The commitment of
the financial sector is continuously monitored and the
agreements will be reviewed every five years.
The financial sector wants to make a substantial
contribution to sustainability projects to help implement
the energy transition properly in various sectors of
the economy and society. The sector is also going to
improve cooperation between various types of financial
An example: The biggest climate impact associated with
ABN AMRO is the mortgage portfolio, with 800,000 homes
that consume energy. ABN AMRO offers mortgage
holders a free energy scan. This gives them a picture
of possible improvements to the home, the costs and
the returns. If necessary, loans can be offered at a
lower interest rate for making the house more energyefficient.
ABN AMRO is aiming for all the homes in its
portfolio to have energy label A on average by 2030.
Homeowners can choose from a wide range of sustainability
measures. An understanding of the expected
payback period is very important here. Investments in
energy savings usually have shorter payback periods
than investments in renewable energy generation.
People who do not expect to stay in their current home
for much longer are better off choosing cavity wall
insulation (pays for itself over 3.3 years) than solar
60

panels (which take 10 years). The payback times for
underfloor insulation (9 years) and roof insulation (7
years) are intermediate.
On the other hand, there are also direct and anticipated
consequences for corporate finance. Banks remain
the key financiers for Dutch SMEs, both medium-sized
companies and small businesses. According to the
Dutch Banking Association, the vast majority of all
outstanding loans (over 80%) are issued by the three
major banks in the category up to €250,000. Those
banks have over 390,000 customers in the category
of loans up to €250,000, plus 60,000 customers with
financing between €250,000 and €1 million and 28,000
customers financed to €1 million or more.
Banks, asset managers, insurers and pension funds
are all actively addressing companies about their
climate policies. This is being done for instance through
Climate Action 100+, an international partnership of
about 600 investors and asset managers aiming to
bring the operations of the 167 most carbon-intensive
companies into line with the Paris Climate Agreement.
On top of that, various companies have made net-zero
commitments under pressure from investors.
reporting give financial institutions the understandings
needed if they are to reduce their CO2 emissions.
Examples are impact investments, lower interest rates
for sustainable mortgage products and facilitating the
construction of green roofs.
At the portfolio level, for example, the PCAF method
is used to show the absolute carbon footprint and
the PACTA method for carbon intensiveness. These
indicators provide different insights and can therefore
be used alongside each other.
CO2 emissions indicators for portfolios
in the financial sector
CO2e intensity indicators
Indicators of
CO2 content
Total / Absolute
CO2 emissions
CO2e footprint
CO2e intensity
CO2e intensity
portfolio weighted
CO2e intensity portfolio
weighted (sectorspecific)
Description
CO2 emissions indicators for portfolios
Total CO2e intensity
of portfolio
Normalised CO2e
footprint per invested
euro
Volume of CO2
emissions per euro
of turnover
CO2e intensity portfolio
weighted
Sector-specific
indicators of financed
activities
CO2e
Indicator
CO2e / € invested
CO2e intensity
portfolio weighted
CO2e / € turnover
CO2e / MWh
CO2/ km
CO2/ m2
CO2/ ton …
Source: KPMG, Summary of climate measurement methods used
in the financial sector in the Netherlands
More than half the financial institutions who have
signed the Climate Commitment already publish details
of the CO2 impact of their investments and financing.
From 2020 onwards, the financial sector's progress
in reducing CO2 emissions is being reported annually.
This approach will mean that the financial sector has
a pioneering role in Europe, aiming to be a role model
for other sectors. The measurements and the annual
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An example is given below of CO2 reporting by ABP, one of the largest investors in the Netherlands.
ABP: PCAF to measure the CO2e emissions of investment portfolios
PCAF at ABP17,18
The ABP pension fund has published the CO2e emissions of its investment
portfolio since 2015. For this purpose, ABP calculates the emissions of
investments in equity and is also going to analyse other asset categories,
such as bonds and property17. The analysis gives an impression of the
total absolute CO2e emissions of all investments.
Highlight: trend analysis of CO2e footprint and sectors
ABP targets a reduction of CO2e emissions using the relative CO2e
emissions. This lets ABP analyse trends in CO2e indicators, such as:
- Absolute CO2e emissions with respect to a benchmark
- Finding the sectors that contribute most to the CO2e emissions
- Reduction in relative CO2e emissions of companies per invested euro,
which can be attributed to a reduction in emissions by companies in
the portfolio
- Developments in relative CO2e-footprint in CO2e intensive sectors
ABP absolute and relative CO2e footprint of equity portfolio
Absolute CO2 footprint against benchmark
Relative CO2 footprint equity portfolio
2014 2015 2016 2017 2018 2019
40
20%
+12%
10%
30
0%
0%
20
-10%
10
-15%
-20%
Target
0
-30%
-28% -28%
2014 2016 2017 2018 2019
ABP shares benchmark
-40%
-37%
Source: ABP Duurzaam Beleggen 2019
ABP trends in sectors
Contribution of sector to the CO2 footprint (2019) Trends in CO2 intensive sectors
100
75
9%
32%
50
17%
25
27%
Basic resources
Utilities
Energy
Industry
Other
0
Basic
resources
Utilities
2014
Energy Industry Other
2019
Source: ABP Duurzaam Beleggen 2019
Source: KPMG, Summary of climate measurement methods used in the financial sector in the Netherlands
The sector is moreover acting jointly with others, for
instance as in the Net Zero Investment Framework,
and over 300 investors worldwide – including many
Dutch financial parties – are working together in the
Climate Action 100+ Initiative. Another example is the
Financieringswijzer providing advice about sources of
funding. Over the coming period, the Dutch financial
sector expects to take many more steps to get publicprivate
investments off the ground.
Real estate investors
The Association of Institutional Property Investors in
the Netherlands (IVBN) promotes the interests of
members who invest in residential property and of
members who invest in:
Offices
Taken as a whole, the IVBN members have about 5 million
m2 of office space in their portfolio. The total stock of
office space in the Netherlands is about 49 million m2.
Shops
IVBN members together have a portfolio of around 4.5
million m2, split into stand-alone shops (high streets)
and shopping malls. The total stock of retail space in the
Netherlands is about 28 million m2.
Here too, all sorts of movements are happening that will
ultimately affect companies and individuals. Here are a few
examples, specifically applicable to office investments:
- IVBN members are developing portfolio roadmaps
(completion by 2021) and reporting on the reduction
62

(in the annual figure) of at least 49% by 2030 and
a carbon-neutral property portfolio by 2050.
- IVBN members are working with tenants to
achieve sustainability targets, for instance
through green leases, sharing data, periodic
consultations with tenants and by undertaking
specific sustainability projects together, such as
installing solar panels.
- IVBN members certify as many buildings as
possible (e.g. with BREEAM, Well, GPR, DGBC
Woonmerk) to give the best possible picture of
the sustainability of the property portfolio.
The rental of retail space provides another example.
The IVBN has reached an agreement with, for instance,
INretail about a standard green lease for the retail
sector. This standard document can be used in addition
to the template lease agreement for retail space from
the Real Estate Council of the Netherlands (ROZ model)
and lays down agreements about furnishing leased
space, installing measuring equipment, sustainable
maintenance and use, data sharing, health and welfare,
and investments (including joint investments). The
standard green lease can be seen as a ‘minimum
standard’ in the market when signing new leases.
The template should let parties reach sustainability
agreements faster and with less discussion about
mutual obligations and efforts.
Private equity
The website of the Dutch Association of Investment
Companies (NVP) states that sustainability aspects
play an increasingly important role in the selection and
management of companies. A term often used in the
investment world when talking about sustainability is
ESG (Environmental, Social & Governance), meaning
that factors such as energy consumption, climate,
health, safety and good corporate governance are
taken into account.
ESG is about the search for a balance between financial
economic results, transparency, social interests and
the environment. There is an increasing amount of
evidence that a good balance yields better results for
the company, the investors and society.
NVP members have played an increasingly important
role in the economy in recent years, and with that
comes a social responsibility. It means that private
investment companies are increasingly taking
sustainability into account in their investment selection
and in the management of their companies.
Sustainability can play a part throughout the
investment process, from selection to exit. Because
private investment companies are usually closely
involved with portfolio holders, they have everything
that is needed for implementing sustainable
investment practices. Sustainability can make a
major contribution to the success of companies and
so help to create value.
Numerous national and international guidelines,
frameworks and other initiatives have now been
developed to draw the attention of private investment
companies to sustainability and provide the tools to
integrate it into their investment processes.
63

64

4
EMISSIONS OF GREENHOUSE GASES
65

GLOBAL EMISSIONS OF GREENHOUSE GASES
Total emissions of greenhouse gases (GHG) grew by 1.5 per cent a year between 2009 and 2018
without allowing for land use change (LUC) and 1.3 per year with LUC, reaching a record high of 51.8
Gt CO2e without LUC emissions and 55.3 Gt CO2e with LUC in 2018. The increase in GHG emissions was
2.0% in 2018 and GHG emissions do not seem to have peaked yet.
Global greenhouse gas emissions from all sources
remained relatively stable over the past decade
(IPCC 2019). Emissions of methane (CH4), the second
Global greenhouse gas emissions (GtCO2e)
60
50
40
30
20
10
0
1990
1995 2000 2005 2010 2015 2018
Land-use change (LUC)
Fluorinated gasses (F-gas)
N2O
CH4
Fossil CO2
most important greenhouse gas, grew by 1.3 per cent
a year and by 1.7 per cent in 2018. Nitrous oxide (N2O)
emissions are increasing steadily, at 1.0 per cent a year
over the past decade. Fluorinated gases (SF6, HFCs and
PFCs) are increasing fastest, by 4.6 per cent a year over
the past decade and 6.1 per cent in 2018.
Source: Olivier en Peters (2019), Houghton and Nassikas (2017) for
emissions from land use change, and Friedlingstein et al., (2019) for
updates dating from 2016 to 2018/Emissions Gap Report 2019
Emissions of greenhouse gases have increased
every year since the global financial crisis in 2009.
The increase in fossil-derived CO2 emissions can be
ascribed to a strong increase in energy consumption.
CO2 emissions from LUC represent about 7 per cent of
the total amount of greenhouse gases (with a large
GHG emissions are dominated by CO2, but 34 per cent of
the overall greenhouse gas emissions, including LUC, are
now gases other than CO2. The OECD economies have
seen only very limited growth of CH4 and N2O, but rapid
growth of fluorinated gases, leading to a slight decrease
in overall GHG emissions. Non-OECD economies saw
increases in non-CO2-related greenhouse gases, which
lead to a general increase in GHG emissions of 2.5 per
cent a year between 2009 and 2018.
uncertainty and year-on-year variability) and have
66

Geographical picture
The biggest emitters of greenhouse gases (excluding
emissions from land use change, due to a lack of reliable
data at a national level) on an absolute basis (left) and
per capita (right)
The top four emitters (China, EU28, India and the USA)
are good for over 55 per cent of overall greenhouse
gas emissions in the past decade, excluding LUC. The
top seven (including Japan, Russia and international
transport) account for 65 per cent; while G20 members
contribute 78 per cent.
China is responsible for more than a quarter (26 per
cent) of global emissions (excluding LUC) and, despite
a significant contribution to the slowdown in global
emissions from 2014 to 2016, emissions from the
country increased by 2.5% in the past ten years and 1.6%
in 2018, reaching a record high of 13.7 Gt CO2e in 2018.
The USA caused about 13 per cent of global greenhouse
gas emissions, with a gradual decrease of 0.1% per year
over the past decade, but an increase of 2.5% in 2018
due to the increased energy demand because of an
unusually warm summer and cold winter.
The European Union, responsible for 8.5% of global
greenhouse gas emissions, saw a steady decline of 1% a
year in the past decade and a decline of 1.3% in 2018.
India, representing 7% of global emissions, kept growing
by 3.7% annually in the past decade and 5.5% in 2018.
The Russian Federation (4.8 per cent) and Japan (2.7
per cent) are the next largest emitters. If LUC emissions
are included, the rankings would change and Brazil
would probably be the biggest emitter. The rankings of
countries change drastically when the emissions per
capita are examined.
Source: Emissions Gap Report 2019 (Fig. 2.3)
67

By 2017, the GHG emissions of the EU had dropped by 22 per cent
compared to the level in 1990 to 4.3 billion tons, while the economy grew
by 58% in the same period, surpassing the objective of 20 per cent set
for 2020. The rate of reduction has slowed in the past few years and
emissions grew by 0.6 per cent in 2017, driven by industry and transport.
The European Union (then 28 countries) had embedded an objective
in its nationally determined contributions (NDCs) of reducing GHG
emissions by at least 55 per cent by 2030, to below the 1990 levels.
Emissions of greenhouse gases per sector
Energy supplies, industry, transport and agriculture are currently the
dominant sources of emissions. Of the 50.8 Gt CO2 eq of emissions in
2016, 17.3 Gt came from energy supplies, 11.4 Gt from combustion and
processes in industry (including the use of fluorinated gases) and 7.0 Gt
from transport (excluding international transport).
Emissions of greenhouse gases per sector in 2016
Land use and forests
4%
Waste
2%
International transport
2%
Buildings
8%
Agriculture
13%
Energy supply
34%
Transport
14%
Industry
22%
Source: UN, Climate action and support trends 2019
68

69

Energy supplies and industry accounted for the bulk
of the increase in emissions between 2010 and 2016.
Emissions of greenhouse gases increased in all sectors
except forestry and other land use, where emissions
decreased and compensated for some of the increase
in other sectors. While most sectors contributed
comparable percentages to the increased GHG
emissions in 2010 and 2016, global transport emissions
grew disproportionately, meaning that the sector was
responsible for a bigger share of the global emissions
in 2016 than in 2010.
Contribution to global increases in emissions
in 2010-2016 per secto
Contribution to emissions growth 2010-2016
50
40
30
20
10
0
-10
-20
47% 45% 29% 19% 6% 3% 0% -48%
Energy supply
Industry
Transport
Agriculture
Waste
Buildings
Land use and forests
The largest share comes from the production of bulk
goods such as iron and steel, cement, limestone, plaster
and other minerals that are usually used as building
products, as are plastics and rubber.
Two thirds of the material is used to make capital goods,
of which buildings and vehicles are the most important.
Although the production of materials consumed in
industrialised countries over the period 1995-2015
stayed within the range of 2-3 Gt CO2e, developing
countries and emerging economies saw faster growth of
material-related emissions (Hertwich 2019). Growth of
investments is accompanied by rapid growth of metal
use. Metal use is growing more rapidly in developing
countries in terms of gross domestic product (GDP) than
in industrialised countries because a larger proportion of
the GDP there is in investments (Zheng et al., 2018).
International transport
-30
-40
-50
Source: UN, Climate action and support trends 2019
Emissions related to producing materials
Producing materials is an important source of GHG emissions.
In 2015, the production of materials caused 11 Gt CO2e
GHG emissions compared to 5 Gt CO2e in 1995, with the
contribution from such production rising from 15% of total
global emissions to 23% over that period (Hertwich 2019).
70

GHG emissions in Gt CO2e associated with the production of materials per material (left) and the first use
of materials in subsequent production processes or final consumption (right)
GtCO2e
10
11.5 GtCO2e
1.4 Plastic and rubber
0.9 Wood products
Services
0.6
Final use
0.8
5
1.1 Other minerals
0.4 Glass
2.9 Cement
0.5 Others metals
Other products
1.0
0.3
Electronics
0.9
Transport
equipment
11.5
GtCO2e
5.0
Construction
0.6 Aluminium
0.9
Metal
products
3.7 Iron and steel
2.0
Machinery
0
Source: Emissions Gap Report 2019 (Fig. 7.1)
Latest projections
The UN produces the “Emissions Gap Report” annually.
At the time of writing this book, the 2021 UN Emissions
Gap Report was the most recent published version;
emissions for 2021 were not included. We will restrict
our analysis that follows in this book to the key results.
However, the Covid-19 pandemic led to an
unprecedented drop in CO2 emissions of 5.4 per cent
in 2020. From 2010 to 2019, emissions of greenhouse
gases grew by an average of 1.3 per cent annually,
both with and without accounting for land use
change (LUC).
Global emissions of greenhouse gases, 1970-2020
Global greenhouse gas emissions (GtCO2e)
60
50
40
30
20
10
0
1970
1975
1980
1985
1990
1995
2000
Source: Emissions Gap Report 2021 (Fig. 2.1)
2005
2010
Fossil CO2 LULUCF CO2 CH4 N2O F-gases
2015
2020
71

Greenhouse gas emissions reached a record high of 51.5
gigatons of CO2 equivalents (Gt CO2e) in 2019 without
LUC emissions, or 58.1 Gt CO2e when including LUC.
Fossil fuel CO2 emissions dominate overall greenhouse
gas emissions, including LUC (66% since 2010). Fossil
CO2 emissions reached a record of 37.9 Gt CO2 in 2019
but fell to 36.0 Gt CO2 in 2020. LUC CO2 emissions have
been 10 per cent of cumulative greenhouse gas emissions
since 2010, though the figures can change considerably
from year to year as a result of climate conditions
(Friedlingstein et al., 2020; Canadell et al., 2021).
The Covid-19 pandemic in 2020 led to an
unprecedented drop in fossil-based CO2 emissions,
in both relative and absolute terms. Global fossil CO2
emissions dropped by 5.4 per cent according to the
dataset for the 2021 report. The changes in fossil
CO2 emissions varied between countries. Despite the
pandemic, fossil CO2 emissions in China grew by 1.3
per cent in 2020, although drops were seen from most
other major emitters, including the USA (10%), the EU27
countries (10%), India (6.2%); international transport
(shipping and aviation) also fell by 20%.
Changes in emissions of greenhouse gases by country
Brazil
China
EU27
France
Germany
India
Italy
Japan
Rest of world
Russian Federation
Spain
UK
USA
World
-25%
-20%
-15%
-10%
-5%
0%
5%
10%
2020/2019 2021/2019
Source: Emissions Gap Report 2021 (Fig. 2.2)
72

Emissions are expected to rise strongly in 2021. In April
2021, the International Energy Agency estimated that
emissions will increase by 4.8% in 2021 after a drop
of 5.8% in 2020 (IEA 2021). Based on data for January
to July 2021, the Carbon Monitor of Liu et al. (2020)
estimates global fossil CO2 emissions to be just slightly
lower in 2021 (by 1%) than they were in the same period
in 2019. Of the large emitters, only Brazil, China and the
Russian Federation showed increases in emissions from
January to July 2021 compared to 2019. Based on data
from the IEA and the Carbon Monitor, it is expected that
fossil CO2 emissions will make a nearly full recovery in
2021, with emission levels only slightly below the record
high of 2019.
Despite the sharp drop in CO2 emissions in 2020, the
concentration of CO2 in the atmosphere grew by about
2.3 ppm (parts per million), in line with recent trends.
There are three reasons why it is unlikely that the
emission reductions in 2020 will be reflected in the
growth rates of GHG in the atmosphere.
1. Although emission levels fell, they were still high
and at much the same levels as in the early
2010s, which means that the amount of CO2
remaining in the atmosphere is expected to be
only marginally less than if emissions were to
keep increasing.
2. CO2 is a cumulative pollutant with a long lifespan,
so we need lasting emission reductions if we are
to see a change in the atmospheric signature.
3. The natural variability of about one part per
million is many times greater than the effect of
reducing emissions by 5.4 per cent.
Similar effects mean that methane and nitrous oxide
concentrations also kept growing in line with the
trends; the increase in levels for them in 2020 was the
highest ever registered. The absence of any change in
atmospheric concentrations despite a record decline in
emissions emphasises that the solution to the climate
problem needs rapid and lasting emission reductions.
In the text of the Paris Agreement (l/CP.21), parties with
timeframes of up to 2025 for their intended nationally
determined contributions (INDCs) would provide a new
NDC, and parties with INDC timeframes of up to 2030
would report or adjust that contribution by 2020.
On 30 September 2021, 121 parties (including the
European Union and its 27 member states, which
submitted a single NDC) representing in total about 52
per cent of global domestic greenhouse gas emissions
in 2018 (Climate Watch 2021) submitted 94 new or
amended NDCs. The NDCs submitted so far reflect
emerging trends for the targets, form, coverage and
conditionality of promises made about greenhouse
gas mitigation, as well as the expected use of market
mechanisms for realising them.
73

Effect of NDCs submitted in 2021 on emissions of greenhouse gases in 2030
New or updated NDC with lower
2030 emissions than prior NDC
New or updated NDC with equal or
higher 2030 emissions than prior NDC
No new or updated NDC submitted
New or updated NDC not comparable
to prior NDC
Source: Emissions Gap Report 2021 (Fig. 2.3)
74

Of the 94 new or modified NDCs, just under half (46 NDCs
from countries that represent 32% of global greenhouse
gas emissions) lead to lower emissions in 2030 than
under the previous NDCs. Eighteen per cent (17 NDCs
from countries that represent 13% of global greenhouse
gas emissions) stated in the new or amended NDCs
that their emissions would not be lower in 2030 than
under the previous NDCs. Thirty-four per cent (32
NDCs from countries that represent 7% of the global
emissions) could not be compared to previous NDCs in
terms of emissions in 2030, mostly due to insufficient
information in the previous NDCs, as transparency has
improved in the current NDCs.
The new or amended unconditional NDCs are estimated
to reduce global greenhouse gas emissions by about 2.9
Gt CO2e by 2030, compared to the previous NDCs. This
estimate includes reductions of about 0.3 Gt CO2e and
is the result of other factors, including lower forecasts
for international aviation and shipping emissions plus
amendments made by countries that expect to exceed
their NDC objectives. If the commitments announced
by China, Japan and South Korea are included, the
reduction goes up to 4.1 Gt CO2e.
If we take a closer look at the G20 members, the
combined impact of the NDCs submitted and the
greenhouse gas reduction targets announced for 2030
is an annual reduction of 3 Gt CO2e compared to the
previous NDCs. By comparison: the total impact of
the new or amended NDC submissions from non-G20
members is an annual reduction of about 0.8 Gt CO2e
by 2030.
Taken as a whole, the G20 members are expected to
fall short of their new or modified unconditional NDCs
and other mitigation undertakings that were announced
for 2030. It is also expected that the G20 members will
fail to achieve their previous unconditional NDCs (as at
November 2020).
As a group, the G20 members are not on schedule
to achieve either their original undertakings or the
new commitments for 2030. Only ten G20 members
(Argentina, China, EU27, India, Japan, the Russian
Federation, Saudi Arabia, South Africa, Turkey and the
United Kingdom) will probably achieve their original
unconditional NDC objectives under the current policy.
Three of those members (India, the Russian Federation
and Turkey) are expected to reduce their emissions
to levels at least 15 per cent lower than their previous
unconditional NDC emission objectives under the
current policy, suggesting that these countries have
considerable space to improve their NDC targets.
As at 30 September 2021, India and Turkey have not
yet submitted new or modified NDCs, while the Russian
Federation submitted a new NDC that does reduce
emissions but still leaves the figure higher than implied
by the current policy.
75

It is worth noting that Canada and the USA submitted
tougher NDC targets although independent studies
suggest that they are not on schedule to reach their
previous NDC objectives under the policy as currently
implemented. These two countries will therefore
need to make considerable efforts to reach their new
NDC objectives.
The emissions gap for 2030 is defined as the difference
between overall global greenhouse gas emissions in
the cheapest scenarios that limit global warming by
2°C, 1.8°C or 1.5°C (to various levels of probability) and
estimated global greenhouse gas emissions resulting
from full implementation of NDCs and the reduction
undertakings that have been announced.
The current policy scenario is expected to reduce global
greenhouse gas emissions by about 55 Gt CO2e by
2030, which is 9 Gt CO2e lower than the policy scenario
from 2010. It is also 4 Gt CO2e lower than the median
estimate for the current policy scenario in the 2020
UNEP Emissions Gap Report. The implementation gap
– the difference between emissions expected in the
current policy scenario and the emissions needed to
reach the NDCs and the reduction undertakings that
have been announced – is estimated at 3 Gt CO2e and 5
Gt CO2e for the unconditional and conditional NDCs and
commitment scenarios respectively.
Changes in projections for GHG emissions by 2030
= Emissions Gap Report 2020
70
60
-4
-4
-4
= Change between
Emissions Gap Report 2020 and
Emissions Gap Report 2021
Global GHG emissions
(GtCO2e/yr) values for 2030
50
40
30
20
-2
-2
10
0
Year 2010
policies
Current
policies
Unconditional NDCs
and pledges
Conditional NDCs
and pledges
2°C
pathways
1.8°C
pathways
1.5°C
pathways
Source: Emissions Gap Report 2021 (Fig. 4.1)
76

The above figure illustrates the emissions gap in 2030
and emphasises the fact that the new and modified
NDCs, together with mitigation commitments that have
been announced, reduce the gap somewhat compared to
previous NDCs but are nowhere near sufficient to bridge
the gap. Compared to previous unconditional NDCs, they
eliminate just 7.5 per cent of the expected emissions in
2030, whereas 30 per cent would be needed for 2°C and
55 per cent for 1.5°C.
Full implementation of unconditional NDCs and
reduction commitments that were announced is
estimated to result in a gap of about 1.5°C or 28
Gt CO2e (range 25-30). This is about 4 Gt CO2e less
than the gap as assessed in the 2020 report (United
Nations Environment Programme (UNEP) 2020), due
to the amended NDCs and the promised reductions
that were announced. If the conditional NDCs and
reduction undertakings that have been announced are
implemented in full, the emissions gap will be narrowed
further by about 3 Gt CO2e. The emissions gap between
unconditional NDCs and the reduction commitments
that were announced and the pathways to stay under
2°C is about 13 Gt CO2e (range 10-16 Gt CO2e), which is
about 2 Gt CO2e lower than last year. Whereas the NDCs
and announced reduction commitments will reduce
global emissions by about 4 Gt CO2e compared to
previous NDCs, the amended 2°C scenario estimate for
2030 is about 2 Gt CO2e less than in previous emissions
gap reports, meaning that the gap will only be narrowed
by about 2 Gt CO2e.
This year, the method for calculating emissions through
to 2100 and the climate model used have been updated
to use improved methods and the latest climate
assessment of IPCC AR6 Working Group I. These updates
alone result in temperature forecasts that are about
0.2°C lower than in previous emissions gap reports;
this should be allowed for when comparing the results
below against past estimates. Continuing the efforts
as implied by the most recent unconditional NDCs and
the undertakings that have been announced is currently
estimated to give warming of about 2.7°C (range 2.2-
3.2°C) with a likelihood of 66 per cent. This implies a
fifty-fifty chance of warming being limited to 2.5°C by
the end of the century (range 2.0-2.9°C) and a 90 per
cent chance of it being limited to 3.3°C (range 2.7-3.9°C).
The net-zero commitments that were announced by
many countries will reduce this estimated temperature
rise by about 0.5°C if implemented in full. The 65th, 50th
and 90th percentiles for the global warming projections
will then be 2.2°C (2.0-2.5°C), 2.0°C (1.8-2.3°C) and 2.7°C
(2.3-3.1°C) respectively.
Even with the implementation of the current NDCs and
all net-zero objectives, there is still a risk of more than
15 per cent that global warming will exceed 2.5°C by the
end of the century and a risk of just under 5 per cent that
it will exceed 3°C.
77

78

5
ENERGY CONSUMPTION AND EMISSIONS
OF BUILDINGS AND CONSTRUCTION ACTIVITIES
79

In 2018, the property and construction sector was responsible for 36% of net overall energy
consumption and 39% of energy-related and process-related carbon dioxide (CO2) emissions, with
11% coming from the production of building materials and products such as steel, cement and glass.
Global share of buildings and construction in overall energy consumption and emissions, 2018
Energy
Other
4%
Transport
28%
Non-residential
8%
Residentia
22%
Emissions
Other
7%
Transport
23%
Residential (direct)
6%
Residential (indirect)
11%
Non-residential (direct)
3%
Other industry
32%
Other industry
31%
Non-residential (indirect)
8%
Construction industry
6%
Construction industry
11%
Source: 2019 IAE Global status report for buildings and construction
Energy trends
Overall total energy consumption in buildings worldwide
increased by 1% in 2018 compared to 2017 and by more
than 8 EJ (about 7%) since 2010. While strong growth
in the principal construction sector came from the
expansion of floor surface area (FSA) and personnel,
outstripping the benefits from energy savings, the
growth in floor area remains disassociated from the
energy requirements, with FSA increasing by 3% in 2018
compared to 2017 and by 23% since 2010. From 2010 to
2018, worldwide consumption of electricity in buildings
increased by more than 6.5 EJ, or 19%.
Emissions from the fuel sources used for generating
electricity, which still include a high proportion of coal
in emerging economies in particular, also increased in
2018. The ongoing drive to make electricity supplies lowcarbon
should therefore be retargeted to low-carbon
buildings with clean energy. Between 2010 and 2018,
sustainable energy sources were the fastest-growing
energy source for buildings; their use rose by 21% (3% of
that in 2017-2018 alone). Use of natural gas rose by 8%
over the same period, both to meet new demand as well
as to supplant the use of coal, which dropped by almost
10% worldwide between 2010 and 2018 (-2% from 2017
to 2018).
Net overall use of energy in the global construction
sector per fuel type
Final energy (EJ)
150
120
90
60
30
0
2010 2011 2012 2013 2014 2015 2016 2017 2018
Fuel type
Source: 2019 IAE Global status report for buildings and construction
Coal
Oil
Biomass (traditional)
Commercial heat
Renewables
Natural gas
Electricity
80

Worldwide, increased energy consumption by end users
is resulting in more emissions because of the sharp
rises in energy use since 2010 for cooling rooms, devices
consumed in heating and cooling, building regulations
should be prioritised in policy, as should technological
improvements.
and hot water. Demand for cooling systems increased
by more than 33% between 2010 and 2018 and by
5% in 2017-2018 alone, while the energy demand for
Overall energy intensity of the global construction
sector per type of source
appliances was up by 18% in 2018 compared to 2010,
and by 11% for heating water. At the same time, demand
for heating systems dropped by 1% from 2010, although
it has remained stable during the past five years at one
third of the total global energy requirements in buildings.
Change in energy intensity since 2010
10%
5%
0%
-5%
-10%
-15%
-20%
-25%
2010 2011 2012 2013 2014 2015 2016 2017 2018
Space cooling
Appliances and
other
Cooking
Water heating
Lighting
Space heating
Energy consumption of the global construction
sector per end usage type
Source: 2019 IAE Global status report for buildings and construction
Final energy (EJ)
150
125
100
75
50
25
0
2010 2011 2012 2013 2014 2015 2016 2017 2018
Space heating
Space cooling
Water heating
Lighting
Cooking
Appliances and other
Factors that influence energy consumption in the
global construction sector include changes in the
workforce, FSA, the demand for energy services
(such as more domestic appliances and cooling
equipment), variations in climate, and the way
buildings are developed and used. Factors that were
Source: 2019 IAE Global status report for buildings and construction
responsible for the higher energy demand since 2010
are FSA, population growth and the use of buildings,
From 2010 to 2018, changes in energy intensity per
unit FSA – as a proxy for energy efficiency – show that
the largest improvements (e.g. energy savings) were in
global averages for heating systems and lighting (-20%
and -17% respectively). Light-emitting diodes (LEDs)
remain important for limiting the energy consumption
for lighting, now that floor surface areas are increasing
and the reduced consumption of heating systems shows
while the improvements in building shells (e.g. better
insulation and windows) and in the implementation of
energy systems in buildings (e.g. heating, cooling and
ventilation) have helped neutralise the growing energy
demand. Nevertheless, the overall energy demand in
buildings keeps increasing and major investments in
efficiency and passive design strategies are needed to
hold back demand and reduce the energy intensity.
that building shells have improved. However, because
floor surface areas are expanding quickly in warmer
countries, demand for cooling is increasing. As better
building shells are essential for reducing the energy
81

Factors influencing energy consumption in buildings, per type of building
150
Residential PJ
Energy saved owing to efficiency
Non-Residential PJ
150
120
120
90
90
Energy saved owing to efficiency
60
60
30
30
0
2010
energy use
Activity Structure Efficiency 2018
energy use
0
2010
energy use
Activity Structure Efficiency 2018
energy use
Source: 2019 IAE Global status report for buildings and construction
Net overall consumption in residential buildings was
responsible for more than 70% of the global total in 2018,
with growth mainly coming from more floor surface
area and the growing population, whereas FSA remains
the key driver of higher consumption in non-residential
buildings. Consumption in residential accommodation
Unlike the previous five years, emissions in the
construction sector seem to have increased to 9.7 Gt CO2
in 2018 – an increase of 2% since 2017, and 7% up
on 2010. Buildings represent 28% of energy-related
CO2 emissions worldwide (39% if the construction sector
is included).
increased by more than 5 EJ between 2010 and 2018,
and by 3 EJ in non-residential buildings. Growth in
residential demand continues to reflect population and
FSA growth as well as development in the emerging
economies and a shift from the traditional use of
biomass to modern fuels (such as electricity, LPG and
Indirect emissions (e.g. from energy generation for
electricity and commercial heating) are responsible for
the lion’s share of energy-related CO2 emissions in the
construction sector, at about 68% of all building-related
emissions from energy consumption in 2018.
natural gas).
Emission trends
Energy-related emissions in the construction sector
worldwide per type of building
The increased emissions in 2016 and 2017 are in line with
the rises in floor surface area and population, as well as
the growth in electricity demand (i.e. indirect emissions).
Emissions from building structures – i.e. related to
Emissions (GtCO2)
10
8
6
4
2
0
2010 2011 2012 2013 2014 2015 2016 2017 2018
Non-residential
(indirect)
Non-residential
(direct)
Residential
(indirect)
Residential
(direct)
manufacturing the construction materials – were 11 Gt
CO2 in 2018, representing 39% of global energy-related
emissions.
Source: 2019 IAE Global status report for buildings and construction
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83

Changes in FSA, population, energy consumption in the
construction sector and energy-related emissions
25%
20%
15%
10%
5%
0%
-5%
Change since 2010
2010 2011 2012 2013 2014 2015 2016 2017 2018
Floor area
Population
Energy
Emissions
Source: 2019 IAE Global status report for buildings and construction
New nationally determined contributions 2020
In 2020, countries were asked to state their new or
amended nationally determined contributions (NDCs)
when recording their efforts to limit national emissions
and to adapt to the effects of climate change; that is
why 2020 was an important year for countries to improve
their NDCs and commit to more ambitious goals. In
addition to NDCs, the scope and powers of construction
decrees about energy performance and certification
policy continue to expand.
Conclusions
- The real estate and construction sectors should
be a primary target group for attempts to reduce
greenhouse gases, as they are responsible for
36% of net overall energy consumption and 39%
of energy-related and process-related emissions
in 2018.
- The higher energy consumption in recent
years was responsible for further increases in
CO2 emissions.
- Although heating systems, heating water and
cooking remain the main sources of demand
for end-user energy in the construction sector,
cooling systems are the fastest growing area.
- Emissions from the construction sector worldwide
are dominated by indirect sources, electricity
generation in particular.
- Despite all the efforts, emissions from the global
construction sector in 2018 rose for the second
consecutive year, by 2% from 2017 to a record
high of 9.7 Gt CO2, due to the increased FSA
and demand for electricity (which is still mainly
generated from fossil fuels).
Reporting on NDCs is an international requirement for
countries, announcing what they have agreed about
limiting emission levels at a national level, where the
increase of the average global temperatures by 2100 is
to be limited to less than 2 degrees Celsius (°C) above
pre-industrial levels, as specified in the Paris Agreement.
To date, the majority of countries (184) plus the European
Union have submitted their NDCs and many of them
(136) mentioned buildings, although most NDCs still do
not list explicit actions relating to energy consumption
and emissions in the construction sector.
To help countries tackle building-related emissions,
GlobalABC has developed guidance for including
buildings in the NDCs. GlobalABC supports ambitious
climate-related actions in the construction sector,
improving the resilience and adaptability of
built-up areas.
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Energy standards for buildings
Energy standards for buildings are requirements set by a legal authority (national or
sub-national) that focuses on reducing the amount of energy used for a specific end
use or building component. In 2018, 73 countries had mandatory or voluntary energy
standards for buildings or were developing them.
Energy standards for buildings have a key role in limiting energy demand in the
construction sector in the long term. For maximum effect, it is important that energy
standards for buildings have teeth and can be progressively improved over the course
of time through effective implementation options. Countries should apply mandatory
energy standards to both residential and non-residential buildings.
Countries that use energy standards for buildings
Mandatory for entire sector
Mandatory for part of sector
Mandatory for part of sector
in major city
Voluntary for part of sector
Code in development
No known code
Source: 2019 IAE Global status report for buildings and construction
Energy certification of buildings involves programmes and policies that evaluate the
performance of a building and its energy service systems. Certification can focus
on assessing the operational or expected/nominal energy consumption and can be
mandatory or voluntary for parts of the specific construction sector or for that sector
in its entirety. The goal of certifying the energy performance of buildings is to provide
information to consumers about their buildings and to gradually create a market for
more efficient buildings.
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From 2018 onwards, 85 countries introduced
certification programmes for the energy performance
of buildings, and several countries and sub-national
jurisdictions also modified their certification policy for
energy in buildings in 2017-2018. The use of certification
programmes is growing, with voluntary certification in
which good performance of buildings is becoming a
popular way of adding value, but there is still no largescale
implementation of full mandatory certification
programmes outside the European Union and Australia.
This means that tracking the energy performance of
buildings over time and disclosure of that information is
still limited in extent.
Countries that use NDCs, energy standards
for buildings or construction certificates
NDC submissions
Building energy codes
Governmental authorities in Europe have either limited
the expansion of investments (e.g. the United Kingdom
and France) or cut it (e.g. Germany). In comparison,
overall investment in real estate in China has grown
by 6% per year since 2015 to more than $1.8 trillion in
2018. Chinese investments focus mainly on residential
buildings, where investments in efficiency rose to $27
billion in 2018, an increase of 33% compared to 2015. In
the United States, investments in both residential and
non-residential buildings grew by 3.8% between 2015 and
2018, to a level of a trillion US dollars, but the proportion
of the investments in improving the energy efficiency
of buildings has been falling, down to 2% of the total
investment by 2018. The real estate market continues to
welcome and invest in green buildings and classification
systems for green buildings. This is a promising sign for
the sector (GRESB, 2019).
NDCs
Buildings
136
194
Country policy 62
Country NDC 46
0 Number of Parties 197
Investments in global energy efficiency and total
expenditure for buildings, 2018
Energy
efficiency
Renewables
51
104
0 Number of Parties 197
Building energy certifications
Country policy
Country NDC
2
84
0 Number of Parties 197
USD 4.5 trillion
Total spending on
buildings construction
and renovation
2018 energy efficiency
spending in buildings
Envelope
Source: 2019 IAE Global status report for buildings and construction
USD 139 billion
HVAC
Investment and financing for
sustainable buildings
Overall energy efficiency spending for buildings was
$139 billion in 2018, a drop of 2% compared to 2017 (IEA,
2019). What prompted this slowdown was stagnation
in investments within the European Union, despite the
United States and China continuing to invest in more
energy-efficient construction systems.
Lighting
Appliances
Source: 2019 IAE Global status report for buildings and construction
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Where are we in 2021?
Using various reports from the IAE, we can look at
buildings, façades, heating and cooling.
Buildings
Direct and indirect emissions from construction activities
plummeted to about 9 Gt in 2020, after increasing by 1%
every year since 2010. Although minimum performance
norms are being tightened, the use of heat pumps
and renewable devices is accelerating and the energy
sector is becoming more carbon-free, the drop in CO2
emissions from the construction sector in 2020 was
largely the result of low activity in the services sector.
Despite the expected recovery of the emissions in 2021
being tempered by the persistent decarbonisation of the
energy sector, buildings remain quite far behind where
they need to be to achieve carbon neutrality by 2050.
To achieve this objective, all new buildings and 20% of
existing buildings need to be carbon-free as early as 2030.
The drop in CO2 emissions in 2020 was principally a
consequence of the Covid-19 pandemic, and of making
energy generation carbon-neutral. Reduced activity in
the services sector (as a result of teleworking, closed
schools and empty hotels and restaurants) was the
prime reason why utility buildings registered the largest
drop in energy demand in history. At the same time, the
increased generation of renewable energy combined with
a lower overall energy demand meant that the carbon
footprint of electricity was lower in 2020 than in 2019. As
economic activity increases again, demand for electricity
will bounce back and the emissions will obviously rise
again in 2021.
Noticeable progress in energy efficiency in the past
year has encouraged the progress in decoupling energy
consumption from the growth of floor surface area created
by the construction sector. Net overall energy consumption
in buildings rose from 118 EJ in 2010 to almost 130 EJ
Emissions (GtCO2)
10
8
6
4
2
0
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020e
Non-residential (indirect) Non-residential (direct) Residential (indirect) Residential (direct)
Source: 2021 Global Status Report for Buildings and Construction | Globalabc
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in 2019 by an annual average of 1%, lagging behind the
average annual 2% expansion of FSA in the same period.
The rapidly increasing end use of energy in buildings
(for cooling systems, appliances and wall socket
loads) is driving the growth of electricity demand in the
construction sector. Whereas electricity was a third of
the energy used in buildings in 2020, the use of fossil
fuels has also increased since 2010 by a marginal
annual average figure of 0.7%.
The drop in energy used per square metre in buildings
resulted from the development of energy codes for
buildings in 80 countries; additional and stricter
minimum energy performance standards (MEPS) for
appliances and a shift towards more efficient heating
technologies such as heat pumps, which reached a total
stock of 180 million units in 2020, an increase compared
to 100 million in 2010.
Nevertheless, the energy intensity of the construction
sector needs to decline five times faster in the coming
decade than it has in the past five years if it is to comply
with the net-zero emissions scenario by 2050. This
means the energy consumption per square metre has to
be 45% less by 2030 than in 2020.
Moreover, the traditional use of solid biomass – highly
inefficient and associated with about 2.5 million
premature deaths due to household air pollution in 2020
– should be completely phased out by 2030.
Final energy (EJ)
Other
6%
22%
Residential
140k
120k
Transport
26%
36%
8%
Non-residential
100k
80k
Other industry 26%
6%
Buildings
construction
industry
60k
40k
Other construction industry 6%
20k
0k
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020e
Space heating
Space cooling
Water heating
Lighting
Cooking
Appliances and other
Source: 2021 Global Status Report for Buildings and Construction | Globalabc
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Since 2010, rising demand for energy services in buildings –
especially electricity for running cooling equipment, appliances and
connected devices – has exceeded the gains from energy efficiency
and decarbonisation. In particular, the proportion of households that
have room cooling worldwide grew from 27% in 2010 to 35% by 2020.
Extremely high temperatures and prolonged heatwaves are
setting records in numerous countries, driving up the demand for
air conditioning. In fact, 2020 was the warmest year on record,
along with 2016 (when a strong El Nino and climate change raised
temperatures around the world), and 9 of the 10 warmest Augusts
(the month when global cooling demand is highest) have occurred
since 2009. Average temperatures in Asia in the summer of 2021
were more than 1.5°C above the pre-industrial average and some
cities elsewhere registered record temperatures, for example Mexico
City (50.4°C on 3 August 2021).
The domestic share of worldwide end-user energy consumption for
refrigerators and air conditioners is now over 80%, up from two thirds
in 2010; just over 75% of lighting is residential. Attaining the net-zero
emissions scenario by 2050 for the construction industry will require
a rapid shift to the best available technologies in all markets by
2030. Historical examples teach us that upgrading pays dividends.
In the European Union, for instance, new refrigerators are now
required to be 75% more efficient than they were 10 years ago, and
labels comparing products were revised in 2021 to help consumers
identify the most efficient ones. For some technologies, however,
progress remains slow. Lighting policies in many countries have not
been revised to phase out halogen bulbs, for example, which are only
about 5% more efficient than incandescent bulbs.
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Final residential energy use covered by labels, 2000-2021
100
80
60
40
20
0
Refrigerators Space cooling Space cooling
2000 2010 2021
Driven by existing policy aimed at reducing emissions
plus several targeted governmental programmes,
investments in energy efficiency in buildings were given
a boost in 2020 and reached almost $180 billion, a
growth of 11% with respect to 2019.
Total investments in energy efficiency in the global
construction sector were expected to increase even
further in 2021. Almost half that investment is for the
construction of new efficient buildings, while the rest
is used for energy-related retrofitting and efficient
appliances.
Economic recovery in the construction and transport
sectors is the key driver of the expected rise in total
investments in energy efficiency globally in 2021.
Despite the recent increase in efficiency investments,
expenditure will need to triple by 2030 compared to the
averages of the past five years if net-zero emissions
are to be achieved by 2050. The scenarios focus on
reaching high ‘energy retrofitting’ percentages of
approximately 2.5% a year by 2030 and making sure
that new buildings that are built in the coming decade
comply with tougher efficiency standards.
The construction sector has a very high carbon
footprint when indirect emissions are taken into
account. About 9% of energy-related and processrelated
CO2 emissions worldwide are the result of using
fossil fuels in buildings; a further 18% comes from
generating the electricity and heat used in buildings,
and another 10% is related to the production of
construction materials.
The entire lifecycle of buildings is therefore directly
and indirectly responsible for about 37% of global
energy-related and process-related CO2 emissions,
which means that emission limits for the entire
lifecycle are needed. American environmental product
declarations are a good example of publicly available
documents that certify the environmental effects of
building materials.
Implementing mandatory carbon-free building
regulations for all new buildings by 2030 is crucially
important if the building exploitation and construction
sectors are to be put on course for achieving the key
milestones for making them carbon-free (net-zero
emissions) by 2050. These norms will have to cover
both the energy intensity and the emissions in the
exploitation and construction phases, as per the most
recent EU policy developments such as the new French
RE2020 norms, backed up by the E+/C label. They must
also include EV recharging, demand management and
flexibility requirements to help buildings accommodate
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variable renewable energy sources and a net-zero
electricity system.
Governments must make sure that their commitments
are both clear and ambitious, giving the market the
right signals for the long term. These undertakings
should set specific policy measures such as tax
and subsidy programmes, to enable and encourage
the implementation of essential energy technology
solutions with the aim of accelerating the transition to
clean energy and reducing costs.
In 2020, the Super-Efficient Equipment and Appliance
Deployment (SEAD) Initiative and the British
government launched the COP26 Product Efficiency
Call to Action to double the efficiency of important
products by 2030, including general-service lighting,
residential air conditioners and residential refrigerators
and freezers. The IEA is developing an energy
performance ladder to bring various policy measures
together to set consistent performance thresholds for
appliance efficiency; the aim is to gradually increase
the policy targets or to switch to the best available
products where possible. Product norms and technical
specifications should be based on quantitative rules
with scientific proof that they comply with the codes
and exceed the MEPS. Using renewable resources
should be promoted through a strict carbon accounting
mechanism during the lifecycle, based on existing
international standards.
The building envelope
About two thirds of countries did not have mandatory
energy codes for buildings in 2020, meaning that
over 3.5 billion m2 was constructed in 2020 without
mandatory energy-related performance requirements
– the equivalent of the entirety of current French real
estate. To stay in line with the scenario for net-zero
emissions by 2050, all countries must set mandatory
carbon-free energy codes for buildings by 2030 at the
latest and all new buildings must meet these standards
from 2030 onwards. This requires 20% of the existing
floor surface area of buildings to be renovated to
that level by 2030, for which the annual renovation
percentages for energy efficiency would have to go up
from under 1% today to 2.5% by 2030, worldwide.
The built-up FSA in buildings worldwide has increased
by about 65% from 2000 to almost 245 billion m2
in 2020. At the same time, the average energy
consumption per m2 dropped by only about 25%. This
means the growth of floor surface area overshadows all
the efforts made in this period.
Performance improvements in building shells are crucially
important for achieving much of the net-zero emission
target by 2050. Although countries are required to
implement mandatory building regulations in the coming
decade in order to meet the net-zero targets, most have
not yet made it an explicit policy priority. Energy coding for
built-up areas sets construction standards for buildings
that meet minimum energy performance requirements.
They are a proven and cost-effective way of improving the
energy performance of both new and existing residential
and commercial buildings.
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Even so, fewer than 85 countries currently have
mandatory or voluntary energy codes for buildings.
Where there are already energy codes for buildings,
ongoing evolution of the norms is important so that the
current and future status of construction practices,
materials and technologies remain reflected in them
and are encouraged. That is why many countries are
modifying their energy codes to make the construction
requirements more rigorous over time.
According to the EU Energy Performance of Buildings
Directive (EPBD), all new buildings should be almost
energy-neutral from 2021 onwards (this rule has
applied to public buildings since 2019). Nearly all EU
member states meet these requirements and have
amended their legislation accordingly.
Despite the various positive signals from many parts
of the world, there are insufficient measures to keep
up with the overall rapid expansion of FSA worldwide.
In the scenario for net-zero emissions by 2050,
all countries must have implemented carbon-free
building regulations by 2030 that apply to both new
buildings and retrofitting of buildings that require
major renovation or work. This is about emissions not
just from construction activities (scope 1 and 2) but
also from the manufacture of building materials and
components (scope 3). More code coverage and strict
supervision of compliance are needed to expand new
high-performance constructions from the current level
of 150 million m2 FSA to over 8 billion m2 by 2030. At
the same time, the energy intensity of buildings will
have to fall six times faster than in the past decade.
In the short term, governmental decisions are needed
to implement the carbon-free construction regulations
in time by 2030. Implementation mechanisms are
also needed to underpin this transition, which can be
promoted e.g. by including compliance practices in
construction regulations. Better building simulators,
training, inspections and checks, as well as
assessments and other stimuli, are important tools for
increasing the level of compliance with construction
regulations. The average retrofitting percentage of
the existing building stock is currently about 1% per
year; such retrofitting generally results in an average
reduction in energy intensity of under 15%. To reach the
scenario of net-zero emissions by 2050, the retrofitting
percentages will have to go up to a level of at least
2.5% by 2030.
Progress is being made on various fronts, however,
such as the EU’s revision of the European building
directive in June 2018 to speed up the renovation
of existing buildings. The European Committee also
launched a ‘renovation wave’ to free up investments
for renovating buildings, aiming to double the amount
of renovation work on buildings in the coming decade.
In 2019, the World Green Building Council network
launched the BUILD UPON2 project in Europe to align
and report about the running renovation efforts
of buildings. Another interesting project is iBRoad
(Individual Building Renovation Roadmaps), which is
developing a tool to outline renovation plans tailored to
individual buildings.
In 2021, the Building Energy Codes working group of
the Energy in Buildings and Communities Technology
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Collaboration Programme (EBCTCP) published a report
on mandatory regulation tools that are used for existing
buildings in IAE member state economies.
In 2020, construction caused 10% of energy-related
and process-related emissions worldwide, with building
shells responsible for more than half of that, twice as
much as in 2000. The requisite quantities of steel and
cement weigh heavily in that figure. Compared to the
expected FSA, demand for cement must fall by over
250,000 tons and 75,000 tons less steel will be needed
by 2030. As a result, demand for steel and cement is
levelling off despite the expansion of the FSA by 2% per
year through to 2030.
Various international initiatives unite countries,
organisations from the private sector and cities in
reducing emissions, such as WorldGBC’s Bringing
Embodied Carbon Upfront, in which eighty stakeholders
in the building and construction chain signed up to a
40% reduction in construction-related emissions per
square metre of new FSA by 2030.
Moreover, some American states (e.g. California)
and cities (e.g. San Francisco, Seattle and New
York) have recently adopted legislation about
sustainable building materials. In California, the Buy
Clean California Act encourages state purchases to
switch to low-carbon materials, and Marin County
has changed its building code to integrate limits on
carbon emissions from concrete.
for the energy performance of buildings. As well as
promoting energy-neutral buildings, the directive
trusts the development of Lifecycle Carbon 8 Energy
Performance Certificates to ensure the reporting and
monitoring of embodied emissions.
This EU directive has already led to action, in
particular the French RE2020 regulation requiring
that all buildings completed after 2022 meet both
energy and carbon norms, whereby the latter is
calculated based on a dynamic lifecycle analysis
that weights short-term emission reductions more
heavily than long-term reductions.
We urgently need measures to implement, upgrade and
enforce energy codes for buildings in order to achieve
the climate objectives. They must deal with the rapid
expansion of the construction industry and improve
the thermal comfort of buildings without significantly
increasing the energy demand, and they also need to
tackle the emissions from both the construction and
the use of buildings. This policy should be developed
now so that it can be in force by 2030 and have all the
supporting tools and market capacity needed to ensure
the regulations for carbon-neutral construction are met
by 2030.
The European Union is also focusing its strategy on
lifecycle emissions accounting in its revised directive
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Sharing knowledge between countries so that energy
codes for buildings can be determined, improved and
enforced will help identify best practices and suitable
technologies, for instance in using improved insulation
techniques for building shells in cold climates to reduce
thermal losses, and using cool roofs, dynamic shading
systems and low-emissivity (low-e) windows to reduce
the energy needed for cooling in warmer climates.
Governments can set a good example by applying
these measures, for example by requiring high-quality
structures for new public buildings and offering
financial incentives to encourage market acceptance
of high-quality solutions.
Building regulations that describe overarching
requirements for the environmental performance of
a building over its entire lifecycle are essential for
reducing embodied emissions. Various international
studies, such as the Building System Carbon
Framework by the WBCSD, provide a framework that all
members of the supply chain can use for quantifying
their emissions and identifying opportunities for
reducing embodied carbon.
Standardised carbon accounting systems based on
this type of framework and international norms (e.g.
ISO14025, ISO14040, EN15804, EN15978, etc.) yield
labels and performance measurements for the entire
lifespan that stakeholders throughout the value chain
for buildings and structures can use.
Data is clearly needed for accurate accounting of the
lifecycle emissions. That is why it is crucial that there
are standardised environmental impact declarations
for products, as this information is the basis for the
carbon accounting systems. Carbon-neutral building
regulations by 2030 should not be limited to just new
buildings but should also cover retrofitting existing
buildings. Governments should promote building
designs that can be adapted to local climatological
conditions, urban forms and construction practices,
and that integrate passive strategies such as natural
ventilation and passive cooling systems.
Moreover, looking at buildings from the lifecycle
perspective – even as early as in the construction
phase – could be encouraged through greater use of
sustainable materials, combined with improved building
design and district and urban planning measures for
building and renovation work. Actions like these can
also reduce the building’s overall carbon footprint.
What is more, the use of simulation and optimisation
tools for designing buildings should be encouraged so
that technological synergies can be achieved during
the building’s design phase. It is important to train
designers, engineers and systems installers so
that best-practice building designs will be approved
more easily.
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Implementing packages for high-quality construction
and renovation demands better access to funding
and the use of innovative business models that
bring borrowers, financiers and regulators together.
Governments can make that possible through policy
interventions plus market regulations to improve
access to funding and reduce the risks of investing
in clean energy.
Measures used can include tax exemptions, subsidies,
loans, auctions and obligations. Governments can
also collaborate with for instance the financial sector,
banks and investors to create a common classification
scheme and a sturdy scientific basis for such
investments. Standardising the verification procedures
so that the uncertainties about evaluations of energy
savings are reduced would help investors understand
the benefits of investments in buildings and the
reproducibility of such savings, making investments
more attractive.
Governments should also expand the R&D funding
for high-quality building shell technology with higher
thermal capacity and thinner insulating layers (e.g.
using vacuum insulation panels and aerogels). It
is about making the building shell more capable of
adapting to changes and variable needs, for instance by
including dynamic envelope components or integrating
renewable energy sources into the building shell.
Heating
The dominance of heaters and boilers based on fossil
fuels has to be broken and their collective market share
has indeed now dropped to under 50%. Despite this
positive development, new boilers that run on fossil
fuels are still a threat to achieving the net-zero emission
goals because they mean extra CO2 emissions that will
still be released in the future (boiler manufacturers are
quick to claim technical operational lifespans of 15 to 20
years). That is why we must stop installing such heating
devices as soon as possible; heating solutions based on
fossil fuels should be completely phased out by 2025 to
comply with the net-zero emission scenario by 2050.
The gradual replacement of conventional oil and gas
boilers with condensation units (typically with 90-95%
yields) has reduced emissions from boilers over the past
decade by 10%. Progress at the current rate is nowhere
near enough to achieve the net-zero objective, though.
The steps being taken towards banning boilers that
use fossil fuels are unevenly spread across the regions.
Norway, Sweden and Finland have already banned the
sale of oil-fired boilers in the past decade. The United
Kingdom will probably follow suit with the publication
of its heat and building strategy paper. Many other
countries, including France, Ireland and Austria, will
ban oil-fired boilers in new buildings by 2025 or earlier.
To stay in line with the net-zero scenario, the share of
clean energy technology such as heat pumps, solar
thermal heating, low-carbon district heating systems
and biomass boilers will need to be more than 80% of the
sales of new heating devices by 2030.
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In addition to improvements to the building shells,
using this low-carbon high-yield heating technology
will help reduce the average energy intensity of heating
globally in the coming decade by about 4% a year. The
combined effects of improvements to efficiency, fuel
shifts and the decarbonisation of the energy sector
should reduce heating-related emissions of buildings
by over 50% by 2030.
In 2020, 180 million heat pumps were in use, compared
to under 100 million in 2010. The bulk of this growth
comes from higher sales of reversible units that can also
be used for cooling, reflecting the increasing demand for
cooling. But in general, heat pumps still meet no more
than 7% of the heating needs in buildings, worldwide.
However, to be in line with the net-zero scenario, 600
million heat pumps will have to meet 20% of the global
heating demand for buildings in 2030.
Cooling systems
Energy consumption for cooling systems has tripled
since 1990, with considerable consequences for
electricity grids, especially during peak periods and
extreme heat events. The global demand for cooling
systems kept growing in 2020, partially driven by
a high need for domestic cooling systems as more
people were spending time at home. Cooling systems
accounted for almost 16% of the end use of electricity
in the construction industry in 2020 (about 1885 TWh).
Although very efficient air conditioners (AC) do exist,
most consumers buy models that are two to three
times less efficient. Implementing standards for energy
efficiency should be capable of improving the energy
performance of AC units by about 50% by 2030 and
help cooling systems get on track to the net-zero
scenario by 2050. Together with improved building
designs, efficiency norms are a key measure for
preventing the lock-in of inefficient units in the
coming decades.
About 2 billion AC units are in use throughout the
world. This makes cooling systems one of the main
drivers of the rising demand for electricity in buildings
and of the additional generation capacity for meeting
peak power demands. Residential units comprise
almost 70% of the total.
Demand for cooling systems has risen by an average of
4% annually since 2000, twice as fast as the demand for
lighting. Higher energy consumption for cooling systems
particularly affects the peak demand for electricity,
especially during hot days when devices are used at full
capacity. Although the performance of cooling devices
is constantly improving and electricity production is
becoming less carbon-intensive, the CO2 emissions of
cooling systems are increasing rapidly, almost doubling
from 1990 to 2020 and reaching nearly 1 Gt.
Globally, the demand for cooling systems increased by
an average of 1% in 2020. With many people working
from home in 2020 and 2021, residential consumption
rose by over 2% while non-residential consumption fell
away by about 0.5%.
These trends may well be very specific to particular
regions. Energy consumption for cooling systems
increased in China and India in both the residential and
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the service subsectors, whereas demand for electricity
for cooling systems dropped in various European
countries in 2020 as a result of a cooler summer.
The AC market in various regions was affected by
lockdowns and heatwaves in 2020. In Europe, for
instance, sales for domestic use rose because a large
proportion of the population worked from home, and in
the United States, the heat waves spurred the demand.
The market for AC units for cooling systems has
evolved a great deal over the past twenty years. China’s
market share has doubled in the last two decades, now
making up 40% of the global market for air conditioners
and cooling systems. While China, the United States
and Japan together account for two thirds of the AC
market, with more than 1 billion units sold in these
countries during the past decade, demand for AC grew
faster in relative terms in India and Indonesia, with
the average number of systems installed annually
increasing by about 10% since 2010.
Despite the rise in demand for cooling in recent years,
there are still differences in AC ownership between
households, depending on household income.
Worldwide, about 35% of the population own an air
conditioner, but only about 12% of the 44% of the
world’s population living in hot climates own an AC
unit. AC ownership exceeds 90% in the US and Japan
but remains under 5% in sub-Saharan Africa and below
10% in India, although the number of cooling days (the
metric used to assess the need for cooling services) is
twice as high in those countries.
Rising living standards, population growth and more
frequent and extreme heatwaves are expected to
create unprecedented demand for cooling over the
coming decade (see The Future of Cooling report).
The number of AC units installed could therefore be
expected to increase by a further 40% by 2030, so
locking in inefficient appliances should be avoided.
To be in line with the scenario of net-zero emissions by
2050, the average efficiency of new AC units for use
on domestic mains electricity would have to increase
by at least 50% in all markets by 2030. In parallel with
increased efficiency of the appliances, cooling demand
in the net-zero scenario is also brought down by better
building design, with 20% of existing building floor area
and all new buildings being carbon-free by 2030.
Passive and nature-based solutions can be some of
the most affordable measures for reducing cooling
consumption. The goal of the Million Cool Roofs
Challenge is to use 1 million m2 of cool roofs (reflective
surfaces that can help lower the indoor temperatures of
buildings). In addition, the authorities in West Sydney,
Australia, have announced a ban on dark roofs to
prevent heat islands arising in future.
101

102

6
CERTIFICATION FOR UTILITY CONSTRUCTION
103

ENERGY CONSUMPTION IN BUILDINGS AND THEIR CONSTRUCTION
While the overall energy consumption of the global construction industry remained the same in 2019
as in 2018, the CO2 emissions associated with operating buildings rose to the highest level ever at
about 10 GtCO2, which is 28% of overall energy-related CO2 emissions worldwide. When emissions
from the construction industry are added, the share is 38% of overall energy-related CO2 emissions
worldwide. The slightly lower proportion of emissions from buildings compared to the 39% in 2018 was
due to the increase in emissions from transport and other industries relative to buildings.
Global share of buildings and the construction industry in final energy and emissions in 2019
28%
Transport
8% Non-residential
buildings
22%
Residential
buildings
23%
Transport
Non-residential
buildings (indirect)8%
3% Non-residential
buildings (direct)
11%
Residential
buildings
(indirect)
5%
Other
32%
Other Industry
35%
ENERGY
5%
Buildings
construction
industry
7%
Other
32%
Other industry
38%
EMISSIONS
6%
Residential
buildings
(direct)
10%
Buildings
construction
industry
Source: GlobalABC - 2020 Global Status Report for buildings and constructions
* Founded at C0P21, hosted by the United Nations Environment Program (UNEP) and with over 150 members, including 30 countries, the GlobalABC is the leading global platform for governments,
private sector, civil society, research, and intergovernmental organizations committed to common Vision: a zero-emission, efficient and resilient buildings and construction sector.
The increased emissions from the construction industry
result from continuing use of coal, oil and natural gas
for heating and cooking in combination with higher levels
of activity in regions where electricity generation is
still largely coal-based. This leads to a stable level of
direct emissions but growing indirect emissions (i.e.
through electricity).
This underlines the importance of a three-pronged
strategy aimed at reducing both the demand for energy
and emissions:
- Radically reducing energy demand in
built-up areas,
- Making the energy sector carbon-free at the
same time, and
- Implementing materials strategies that reduce
carbon emissions during the lifecycle.
104

For the first time in three years, expenditure on energyefficient
buildings rose in 2019, namely by 3% to $152
billion. However, this is still only a small fraction of
the $5.8 trillion spent in the construction industry.
Investments in energy efficiency are lagging behind
investments as a whole in the sector, so more effort is
needed to make buildings carbon-free. For every dollar
spent on energy efficiency in the building industry, 37 are
spent on conventional construction solutions.
Even so, there are positive signs that the
decarbonisation of buildings and energy efficiency
are gaining ground in financial investment strategies.
Financial institutions and property companies realise
the huge potential for growth and the investment
opportunities in sustainable buildings.
Of the 1,005 property companies, developers, REITs
and funds that reported to the Global ESG Benchmark
for Real Assets (GRESB) in 2019, jointly representing
managed assets of $4.1 trillion, 90% take account of
the assessment standards for green construction and
operation in their projects.
The construction and operation of buildings accounted
for the biggest share of final energy consumption
worldwide in 2019 (35%) and of energy-related CO2
emissions (38%) in 2019. The building stock’s share in
global energy and emissions has been stable since 2018
(IEA 2020b). In the comparison with the 2018 Buildings
GSR, it should be noted that the slightly lower proportion
of emissions from buildings compared to the figure of
39% in 2018 was due to the increase in emissions from
transport and other industries relative to buildings.
Construction industry: final energy consumption
worldwide, 2010-2019
Final energy (EJ)
150
120
90
60
30
0
Source: IEA (2020b)
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Fuel type
Coal
Oil
Biomass (traditional)
Commercial Heat
Renewables
Natural gas
Electricity
Green buildings form one of the biggest global
investment opportunities of the coming decade,
estimated at $24.7 trillion in 2030 by the International
Finance Corporation (IFC). Governments play a key role in
the exploitation of this opportunity.
The total energy consumption in the operation of
buildings was about 130 EJ – about 30% of overall final
consumption – plus another 21 EJ for buildings and
construction, or 5% of the total demand. Electricity
consumption in buildings currently accounts for about
55% of global electricity consumption (IEA 2020b). 2019
was the first year since 2012 to see energy consumption
in buildings remain stable, and the energy intensity in
relation to the floor area improved (IEA 2020a).
105

Emissions due to buildings and their
construction
Direct energy-related emissions and those related to
the use of energy in the construction of buildings rose
to slightly more than 3 GtCO2 and 6.9 GtCO2 in 2019,
while the combined direct and indirect energy-related
emissions due to the use of buildings rose to around 10
GtCO2 in 2019, or about 28% of total global CO2 emissions
(IEA 2020b). In addition, the production, transport
The increase in emissions in the construction industry is
the result of the continuing use of coal, oil and natural
gas for heating and cooking in combination with higher
levels of activity in regions where electricity generation
is still largely coal-based. This leads to a stable level
of direct emissions but growing indirect emissions (i.e.
through electricity) (IEA 2020a). Although the direct
emissions of electricity are low, it is still mainly generated
using fossil fuels such as coal and natural gas.
and use of all the construction materials for buildings
resulted in energy-related and process-related CO2
emissions of around 3.5 GtCO2 in 2019, which is 10% of all
emissions in the energy sector (IEA).
Global building-related emissions, 2010-2019
10
8
6
4
Emissions (GtCO2)
Non-residential
(indirect)
Non-residential
(direct)
Residential
(indirect)
Emissions data for the use and construction of buildings, 2019
Buildings use phase 9953
Coal 496
Oil 939 9%
Natural gas 1663
2019 (MtCO2) Share
direct emissions
Electricity and heat 6855 19% indirect emissions
Buildings construction 130
Construction energy use 130
Material manufacturing 3430
Cement- and steelmanufacturing
for construction
2038
Other 1 391
Buildings and construction
value chain
10% indirect buildings and
construction value
chain emissions
13512 38% of total energy related
emissions
2
0
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Residential
(indirect)
Source: IAE 2020b (Energy Technology Perspectives 2020)
Source: 2019 Global Status Report for Buildings and Construction
The IEA estimates that the combined energy-related
emissions due to buildings and the building industry
account for 38% of global CO2 emissions. Emissions
from the production of building materials and their use
in construction are mainly driven by the production of
cement and steel (IEA 2020b); growth in use of those
materials is a key factor pushing up building-related
The design and types of new buildings (high-rise) have
led to higher demand for steel and cement, although
such buildings may have a longer service life thanks
to the use of these materials. The global construction
industry accounts for about 50% of the demand for
cement and 30% for steel. This shows the importance of
extending the service life of buildings, reducing the use
of those materials or replacing them with materials with
a lower embodied carbon content.
carbon emissions.
106

Numerous analyses show that decarbonisation of the
sector is possible, but it requires clear roadmaps that
need to be developed and implemented to accelerate the
necessary transition to carbon-neutral buildings by 2050.
Countries can support this transition in various ways,
for example by implementing progressive building
regulations, with market rules and by facilitating
investments in energy efficiency in existing buildings. An
analysis by the Climate Action Tracker (CAT) shows that
the reduction in emissions needs to be taken further.
According to a recent report, the reduction in emissions
from buildings needs to be substantial and to be
achieved quickly, with considerable reductions by 2030
and almost complete decarbonisation by 2040. Based on
the average of all the scenarios modelled by the CAT, the
overall reduction in direct CO2 emissions caused by the
sector in comparison with 2020 must be at least 45% by
2030, 65% by 2040 and 75% by 2050.
The indirect emissions due to the energy sector need
to decrease even faster. The CAT analysis shows that
completely eliminating emissions due to buildings by
2050 is possible using existing technological solutions.
However, this demands considerable investments
in carbon-free heating and cooling sources and
improvements to the building shell. In the scenario for
sustainable development, the IEA estimates that direct
emissions will not fall by more than 30% by 2030 and
that total direct and indirect emissions will decline by 3.5
Gt CO2 in the period 2019-30 (IEA 2020a). However, in
the scenario of net-zero emissions by 2050 (NZE2050),
focusing on the action needed to ensure the energy
sector achieves net-zero emissions by 2050, the IEA
reports that the direct CO2 emissions due to buildings
will need to decline by 50% by 2030 and the sector’s
indirect emissions must go down by 60% by 2030, driven
by reductions in emissions due to energy generation
(IEA 2020a). These efforts would need to achieve annual
reductions of about 6% in the construction industry’s
emissions between 2020 and 2030. To put that into
perspective, CO2 emissions from the global energy sector
fell by an estimated 7% during the pandemic.
Most countries still need to submit their second nationally
determined contribution (NDC); there is a good chance
that they will include specific mitigation policies for
buildings and will use codes, standards and certification
guiding the sector towards zero carbon emissions.
At the start of 2020, countries were asked to submit their
new or revised NDCs to the secretarial office of the UN
Framework Convention on Climate Change as part of the
five-year cycle of reviewing countries’ objectives and
undertakings following the Paris Agreement.
107

Buildings sector emissions coverage in NDCs, 2018-2020
New in 2020
New in 2019
New in 2018
NDC: >75% coverage
NDC:

109

Buildings energy codes by jurisdiction, 2018-2019
Mandatory for entire sector
Mandatory for part sector
Mandatory for entire sector
in major city
Voluntary part of sector
Code in development
No known code
This map is without prejudice to the status of or sovereignty over any territory, to the delimitation of international frontiers and bounderies, and to the name of any territory, city or area.
Source: GlobalABC/IEA/UNEP (2019). All rights reserved. Adapted from “Energy efficiency policies: Buildings”.
Although energy codes for buildings are more common in
high-income countries, considerable progress has been
made around the world in formalising and regulating the
construction industry.
Certification for green or sustainable construction plays an
important role for developers and owners who want their
buildings to be distinctive as well as rewarding them for their
efforts towards sustainable construction and operation.
In the GlobalABC members’ survey, the respondents
stressed the main developments in both energy codes
and energy certification schemes for buildings. A
substantial majority of respondents (79%) reported that
their region or country had an energy code for buildings,
whereas only 14% said that this was not (or not yet)
the case. Certification for a building’s performance in
terms of energy and/or sustainability gives a signal to
the market and provides information to sustainabilityaware
investors, lessees, policymakers and consumers.
The use of certification allows you to assess and
compare how well a building satisfies predefined
criteria for a norm or meets relevant requirements. The
certification of buildings is a tool for quality assurance
during the design, construction and commercial
operation. Given the lack of holistic, ambitious legislation
in almost all countries and assuming the certification
systems embrace the emissions targets of the Paris
Agreement, such certification systems can fill that gap
and act as an instrument that transforms the market and
110

Buildings energy certification programmes by jurisdiction, 2017-2018
Partial mandatory with
widespread voluntary
Partial mandatory
Widespread voluntary
Widespread voluntary with
only a few projects
No certification
or no infotmation
This map is without prejudice to the status of or sovereignty over any territory, to the delimitation of international frontiers and bounderies, and to the name of any territory, city or area.
Source: IEA (2019b). All rights reserved. Adapted from “Energy efficiency policies: Buildings”
pushes it and its stakeholders towards more ambitious
building practices.
Increasing awareness and growing demand from the
financial sector could lead to certification being used
to verify the requirements for sustainable financing
practices such as the EU’s taxonomy initiative.
Ultimately, the certification of green buildings should
be aimed at constantly raising the bar for quality and
introducing transparency. The number of certification
standards for green and sustainable buildings continued
to grow in 2020 and more buildings than ever received
a certification label. Globally, labels such as LEED,
BREEAM, Passivehouse, DGNB and EDGE continue to be
used on a large scale.
Certification of green buildings and other sustainability
labels aimed at buildings with low or near-zero emissions
and energy consumption are an important ingredient
in achieving a low-carbon building stock, but the
certification must be based on common definitions and
used in combination with mandatory building regulations
and progressive policies. Many of these schedules have
been made publicly available and they certify buildings
that achieve net-zero emissions based on performance
data. They include nine standards from Green Building
Councils, such as the US GBC’s LEED Zero, EDGE Zero
Carbon certification and ILFI Zero Carbon certification.
111

Investing in green buildings
The global incremental investment in energy efficiency
in buildings was about $152 billion in 2019, an increase
of 3% with respect to 2018 (IEA 2020c). This is a positive
change after investment remained flat in 2017 and
2018 at about $148 billion. However, the percentage
increase is less than the rate of growth of investments
in the construction of buildings, which was 4.9%, to
$5.9 trillion.
This increase in investments in energy efficiency is
driven by both a rise in the investment activity in the
construction industry on the world market, with an
increase of 4.9% compared with 2018, and continuous
policy efforts, particularly in European countries and
China, to steer more investments towards the energy
performance of buildings.
Annual growth between 2014 and 2018 in the energy
efficiency of buildings, measured as an improvement
in the energy intensity, was 3.5%. This is in line with
the 3% growth that is required to achieve the Paris
targets and Sustainable Development Goal 7. However,
this percentage is less than the rate of growth of
investments in the construction of buildings in the
same period, namely 4.5%. That means that the growth
in investments in energy efficiency is not keeping pace
with the construction of buildings worldwide, resulting
in little change in the energy consumption by the global
building stock.
Building construction and energy efficiency
investment and breakdown
Source: IEA (2019b). All rights reserved. Adapted from
“Energy efficiency policies: Buildings”
Incidentally, a striking but not entirely unexpected
feature is the big part played by the building envelope
or shell.
USD
5.8
trillion
Total spending on buildings
construction and renovation
Cooling in buildings
The energy requirements for cooling spaces could
increase by a factor of three over the next 30 years (IEA
2018), especially in hot and tropical countries. Houses
account for more than two thirds of this increase.
Global annual sales of air conditioning systems have
increased nearly fourfold since 1990. About 2.8 billion
people live all year round in places that have average
daily temperatures in excess of 25°C and only an
estimated 8% of them have air conditioning (GlobalABC
2018, IEA 2018).
USD
152
billion
79 Envelope
39 HVAC
18 Lighting
16 Appliances
2019 energy efficiency spending
in buildings (USD billion)
This trend will continue and intensify, driven by rising
incomes, the expected doubling of building floor area
by 2060 (IEA 2019a) and a warmer planet with higher
temperatures and increasingly frequent heatwaves.
112

It will remain a major challenge to satisfy the demand
for cooling in the future because of the vast quantity
of building spaces that are being constructed around
the world with little capacity for adapting to the local
climate. Badly designed buildings using steel, concrete
and glass can be liable to overheating without the
correct thermal breaks, sun shading (dynamic or
otherwise), ventilation or insulation. As a result, they
need excessive amounts of energy for mechanical
cooling in order to offer thermal comfort. Another
challenge is the capacity of the electricity grid, which is
often at its limit even in developed countries.
Better building designs can reduce or even eliminate
the demand for energy to cool spaces. Climateadjusted
building envelopes, colours on the exterior,
windows, natural ventilation, orientation and vegetation
offer substantial opportunities for reducing the demand
for energy for cooling purposes.
If buildings are adapted to suit the local climate and
passive cooling technologies are used, the buildings
can stay cool naturally. Variations depend on the
climate zone, the local building culture and the
utilisation of the building.
While there are many variations, the following principles
apply: in humid climates, light to medium-heavy
structures and open, spacious layouts ensure constant
natural ventilation; in dry climates, buildings have to
be very solid to keep out the heat during the day and be
able to cool down naturally at night. However, climate
change is speeding up, which means such rules of
thumb are less significant.
A key design aspect is determining an appropriate
orientation for buildings with respect to the sun.
Windows should be in shadow and the ratio of window
area to wall area must be adjusted to suit the climate
zone, while still guaranteeing sufficient daylight.
113

Certification
The website www.buildings.com gives an overview of well-known international labels for buildings.
Name Process Initial certification Renewal Focal areas Building types
BOMA 360
PERFORMANCE
PROGRAMME
Gather all required
documentation. Create
an online account and
complete the application
form. Applications are
accepted on a daily basis
and designations are
awarded quarterly.
Fees are based on surface
area, expressed in square
metres. BOMA members
receive a substantial
discount and certifying ten
or more buildings at the
same time qualifies for a
15% portfolio discount on the
application fees.
Renew every three years to
maintain the designation.
Buildings must also have
their performance verified
annually but there is no fee
for the annual verification.
Building operations and
management, personal
safety/security and risk
management, training
and education, energy,
the environment and
sustainability, and tenant
relations and community
involvement.
Occupied commercial office
and industrial buildings.
Multi-purpose buildings are
only assessed with respect
to the office portion.
BREEAM
Register your project
and complete the selfassessment.
Receive an
unverified score. Have an
assessor verify the score to
achieve full certification.
$1,000 for access to the
self-assessment tools. $750
per certificate for each of
the three parts.
$250 each for renewing
certificate without changes.
This can be done up to two
times. After two renewals
or after far-reaching
changes, recertification is
required. This costs $750 per
certificate.
Management, health and
welfare, energy, transport,
water, materials, waste,
land use, and ecology and
pollution.
All existing commercial
buildings.
CLASS-G
Complete the selfassessment
checklist and
publish it. Order a plaque.
Other registered users
can submit comments for
review, which will be studied
by you and Class-G.
Flat annual subscription rate
of between $300 and $1,200
depending on the number of
locations and the length of
the commitment.
The subscription is renewed
annually.
Air and health, energy,
water, materials and waste
reduction.
Any building or business that
is committed to sustainable
operations. A separate
scorecard is available for
data centres.
ENERGY STAR
FOR BUILDINGS
Enter building data into the
Portfolio Manager, which
indicates whether you might
be eligible. If so, complete
the verification process
and apply. Eligible buildings
must score at least 75 out
of 100 and are verified by an
engineer or architect.
Awarded once a year. No fee
to apply.
Can be renewed annually.
Buildings that earn the
ENERGY STAR can apply
again one year after the date
of the last energy data that
was sent with the previous
year’s application.
ENERGY STAR is a singleattribute
certification
focusing on energy use, but
the Portfolio Manager tool
can also track waste and
water.
21 building types are eligible
to receive a score.
FITWEL
Evaluate your building using
the appropriate scorecard.
Benchmark the performance
and track it over time.
Upload documentation
for assessment by two
independent reviewers.
$500 per year for
registration and a one-time
project fee of $6,000.
Reduced rates are available
for companies that certify a
whole portfolio.
Certification is valid for three
years. Recertification costs
$500 plus 80 per cent of the
applicable certification rate.
Location, building access,
outdoor spaces, entrances
and ground floor, stairwells,
indoor environments,
workspaces or residential
areas, shared spaces, water
supplies, food services or
grocery stores, vending
machines or mini-markets,
emergency procedures.
For offices or multi-family
units.
GREEN GLOBES
Use the cloud-based
assessment tool to gather
data and implement
best practices. When you
are ready for a formal
evaluation, a third-party
assessor will visit your
premises to provide
guidance and quality
assurance. Your score and
rating are contained in a
final report.
Registration costs $1500.
The costs per square
metre depend on the
building’s dimensions and
characteristics, the type
of certification, and the
type and number of formal
assessments you need.
Green Globes encourages
recertification after three
years.
Energy, water, waste and
resource management,
emissions and pollution,
quality of the indoor
environment and
general environmental
management.
Any fixed-site commercial
structure of more than
37 m2, with specialised
resources available for
offices and healthcare
sector buildings.
LEED FOR
BUILDING
OPERATIONS
AND
MAINTENANCE
Register to gain access to
the tools and resources
needed to earn certification,
including an online project
management tool.
Flat registration fee, plus a
certification fee that varies
depending on the project
size and the rating system.
The term varies, depending
on the LEED specialisation.
LEED O+M requires ongoing
recertification to ensure
that the high performance
continues. The other LEED
systems do not require
renewal.
Location and transport, site
management, water, energy,
condition of the materials,
quality of the indoor
environment.
All commercial and
institutional buildings,
although some (data
centres, hospitality sector,
schools and others) have
tailored rating systems.
114

Name Process Initial certification Renewal Focal areas Building types
LIVING BUILDING
CHALLENGE
Register your project
and gather the required
documentation for all 20
mandatory imperatives.
An independent auditor will
perform a content review
and site visit on which your
certification will be based.
Costs are based on the
building size, type of
certification (full versus
partial or zero-energy only)
and whether you need a
preliminary audit.
Not needed. Issued once.
Place, water, energy, health
and happiness, materials,
equity and beauty. Partial
certifications are available,
as are zero-carbon and
zero-energy designations.
Any building type that can
meet the requirements.
NATIONAL
GREEN
BUILDING
STANDARD
Work out your building’s
score with a downloadable
spreadsheet. Hire an
accredited verifier to
conduct two inspections.
A verification report will
confirm whether you are
eligible for certification.
Projects are charged a flat
fee for each building and
an additional $20-30 per
apartment.
Not needed. Issued once.
Plot and site development,
resource efficiency,
energy efficiency, water
efficiency, quality of the
indoor environment and
homeowner education.
Multi-family, including
apartment blocks, housing
with shared facilities and
the residential portions of
mixed-use buildings. New
construction or renovation
only.
PARKSMART
Register and participate
in a planning phone call.
Collect and submit the
documentation. Get your
project reviewed and sign off
the final review.
$1200-1500 for registration,
$4500-6500 for
certification.
Certification is valid for three
years. The recertification
process is currently under
development.
Management, programmes,
and technology and
structure design.
Any multi-storey parking
structure.
PASSIVE HOUSE
INSTITUTE US
Submit a certification
contract and register
with the Passive House
Institute. Upload the project
documentation to Dropbox
as instructed. Passive
House will review the project
performance and issue a
certificate.
Small building fees start
at $1500. Larger buildings:
$4000-33,125.
Not needed. Issued once.
Airtightness, energy source
and climate conditioning of
the space.
Commercial, mixeduse,
campuses and
communities, as well as
multi-family.
PEER
Register and submit
payment. Complete
your application with
documentation and submit
it for review. Certification is
awarded, pending the review
results.
$1,200 for registration,
$8000 for certification.
Data must be submitted
annually to maintain the
certification. Recertify
formally every five years.
Reliability and resiliency;
operations, management
and safety; energy
efficiency and the
environment; electricity grid
services; innovation and
exemplary performance;
and regional priority.
All sorts of power systems,
including campuses, microgrids,
critical infrastructure,
city grids and utility
company premises.
SERF
Hire a professional to
guide you through the
certification process and
verify performance. Submit
the verified data to SERF,
who will evaluate your
application and issue the
certificate.
Initial fees of $4000-12,000.
Annual renewal fee of
$195-495. If you have
made changes to your
building that could affect
performance, recertify it
under the current criteria.
18 or more categories,
including energy and water
efficiency, janitorial, waste
management and recycling,
lighting, air quality,
transportation, landscaping
and grounds management,
plus some categories for
specific building types.
Offices, multi-family,
retail, manufacturing and
distribution, hospitals and
institutional facilities. SERF
may also work with buildings
that do not fit these
categories.
SUSTAINABLE
SITES
Register your project to
gain access to the SITES
worksheets. Collect and
submit the documentation.
GBCI will conduct a final
review and issue the
certification.
$2500-3000 for registration
and $6500-9000 for
certification.
Not needed. Issued once.
Site context, pre-design
planning, water, soil and
vegetation, materials
selection, human
health and wellbeing,
construction, operations and
maintenance, education and
performance monitoring,
and innovation.
New construction and
existing sites that have been
renovated, with construction
in the last 2 years. Minimum
185 square metres.
TRUE
ZEROWASTE
Register your project.
Complete the
documentation and submit
it for review. After your
documentation is reviewed,
an assessor will visit to verify
compliance. A final review
gives you the opportunity to
add additional credits.
$1250-1500 for registration.
Certification requires a
custom quote.
Waste flow separation data
must be submitted annually.
Achieving net-zero waste
status.
Any physical facility,
including campuses.
WELL BUILDING
STANDARD
Register with WELL Online
and develop solutions
customised to your project.
Accredited professionals
review your documentation
and verify performance
onsite. A laboratory
checks the technical
measurements.
WELL v2 ranges from $1500-
10,000 depending on the
project type and size. WELL
v1 is also still available.
Recertification fees for v2
range from $1.29 to 1.61
per square metre, or flat
fees from $3770-6525 for
buildings under 4645 square
metres.
The new v2 has expanded
the category list to include
air, water, nourishment, light,
movement, thermal comfort,
sound, materials, mind,
community and innovation.
WELL v2 can be applied
to any building type,
including those that were
tested in pilot versions of
v1 (multi-family residential,
commercial kitchens, retail,
educational facilities and
restaurants).
115

Conclusions after analysing the overview:
- Depending on the approach, some construction
certification systems are based on selfassessment;
institutions then offer software or
web-based tools for the purpose. Other systems
are based on third-party certification.
- Eleven of the total of sixteen certification
systems apply to commercial and institutional
buildings.
- Many of the systems were set up after 2000 but
no figures are given for the number of buildings
registered or certified. Numbers are only
published for BREEAM and LEED, both of which
work with certifications and assessments as a
form of accreditation. The criteria used mainly
apply to energy, water, pollution, materials,
quality, emissions, management and processes.
- BREEAM was established in 1988 in the UK.
It is offered by the BRE Group and claims to
have certified 575,000 buildings and registered
2,300,000 buildings in over 85 countries.
- In the case of LEED, founded in 1998 in the US
and offered by the Green Building Council, the
numbers are considerably lower. Around 50,000
buildings have been certified and over 500,000
buildings are registered.
BREEAM
BRE have been working on the development of
standards for the built environment since 1921 and the
group has grown significantly, especially in the last few
years. They operate internationally and have offices,
representatives and partners all over the world. BRE is
part of the BRE Trust, which uses most of the profits
from services to fund new research and education
programmes. The independent certification body
(BRE Global) provides impartial third-party certification
services to companies, manufacturers and service
providers worldwide for domains such as fire safety
and security, environmental products, building
information modelling (BIM) and management systems
such as BREEAM.
One specific focal theme within BREEAM certification
is 'health and wellbeing'. A BRE Trust report published
in October 2019 focuses inter alia on circadian lighting.
The aim of circadian lighting is to improve alertness
during working hours with brighter lighting and then to
help relaxation with less bright and warmer light.
The BRE Trust also regularly publishes about three
essential aspects of indoor spaces: indoor air quality,
lighting and acoustics. The health and wellbeing of
people in non-residential buildings have now become
an integral part of BREEAM certification.
116

The latest published data for BREEAM certificates
actually issued for non-residential buildings currently
dates back to 2020.
Number of ‘in use’ certificates issued, by building type
Accommodation 7.22%
Other types 4.12%
A total of 20.6 million m2 of floor area was certified in
the Netherlands through to the end of 2020; 13.4 million
Industry 11.34%
Conference 4.12%
2020
Offices 46.39%
m2 of that was for buildings in use and 7.2 million m2
for new buildings. The totals include both residential
and non-residential buildings, although the number of
Shops 26.80%
BREEAM-certified residential buildings is very small.
Source: BREEAM-NL website
The number of buildings per year that acquire a BREEAM
certificate is increasing rapidly but is still only a small
fraction of the total building stock.
Number of BREEAM certificates in the Netherlands
Number of certificates issued for ‘new construction’,
by building type
Other types 10.00%
Offices 19.00%
Shops 1.00%
2020
2018 2019 2020
350
300
Industry 70.00%
250
200
150
100
50
0
102 128 137 293 273 320
New construction
In use
Source: BREEAM-NL website
As in other systems, the measures and facilities in the
building are categorised using a points system. The
points sum up to give a total that determines whether
certification can be granted and to what level. BREEAM
certification also works with various levels.
Source: BREEAM-NL website
Looking at the totals for the categories that play a role
The following illustrations give a picture for each type
of building, based on the number of certificates issued.
This clearly shows that it is more common for offices
and industrial buildings to be certified.
in certification, there are various categories where
applying dynamic sun protection could be interesting.
117

BREEAM-NL New construction 2020 V1.0
category or sub-category score type of building
Health
HEA 01 Visual comfort 5 points Offices/education/care sector
HEA 04 Thermal comfort 3 points Offices/education/care sector
Energy
ENE 01 Energy efficiency 15 points Offices/education/care sector
ENE 04 Passive design and environmental impact 3 points Offices/education/care sector
BREEAM-NL ‘In use’ V6.0.0 Non-residential construction
category or sub-category score type of building
Health
HEA 01 Daylight 4 points Offices/education/care sector
HEA 04 Counteracting light nuisance 4 points Offices/education/care sector
HEA 06 Visibility (view out) 3 points Offices/education/care sector
Management
HEA 14 8 points Offices/education/care sector
Energy
ENE 01 Energy efficiency 40 points Offices/education/care sector
LEED
The US Green Building Council was founded in 1993
with the mission of promoting sustainability practices
in construction. Since the rating system was introduced
in 2000, it has become an international standard for
environmentally friendly buildings.
LEED provides guidelines for constructing healthy, highly
efficient and cost-effective green buildings. LEED covers
all types of buildings and construction phases, such as
new builds, furnishing, operation and maintenance as
well as the shell or envelope construction. The system
is very similar to BREEAM and is based on points that
can be earned for facilities, implementations and
specifications in various categories. Certificates are
given when a certain minimum is attained, and the
certification itself has various gradations depending on
the number of points achieved.
The vision of the US Green Building Council (USGBC)
is that buildings and communities should protect,
maintain and revitalise the health and vitality of all
life within one generation. Its mission is to transform
the way buildings and communities are designed,
constructed and managed with the aim of making
a human-friendly and environmentally-friendly,
healthy and prosperous environment that improves
the quality of life.
The US Green Building Council was founded in 1993
by Rick Fedrizzi, David Gottfried and Mike Italiano
with the goal of promoting sustainable thinking in
the construction sector. Other countries around the
world have followed suit and established similar
organisations, all headed by a Green Building Council.
118

The growing interest led to the formation of the ‘United
Nations of Green Building Councils’, whose mission is to
support and unite Green Building Councils around the
world with a shared voice and purpose. Green Building
Councils are independent, non-profit organisations that
work in the construction sector. They work to promote
green building in their own countries, as well as joining
forces with other Green Building Councils to achieve
economic, social and environmental goals on a larger,
global scale.
In April 2018, the World Green Building Council released
a new report highlighting the tangible economic
benefits of green construction. The report shows
that users become more satisfied when companies
implement new health, wellbeing and productivity
standards in existing green buildings. The report
evaluates health and wellbeing features as integrated
into the facilities, such as improved circulation of fresh
air, acoustic privacy, better incident daylight and the
use of biophilic design elements such as green walls
and plenty of indoor plants.
Companies that added health and wellbeing features to
green-certified buildings found that absenteeism fell,
operating costs went down and employees felt more
productive and healthier.
The report is based on a survey of more than 2000
industry participants including architects, engineers,
building contractors, owners, specialists, consultants
and investors from 86 countries. It aims to analyse the
level of green activity, the impact of green standards in
construction on business operations, the measures that
are most likely to lead to further growth of the green
market and the potential obstacles to that.
A total of 45 Green Building Councils (GBCs) from
around the world took part in the study. The report
highlights nineteen countries in particular, spread
across six continents, that are each expected to show
significant growth in the percentage of green projects.
There is extra emphasis in this research on the social
impacts, such as higher productivity among employees,
creating a sense of community and supporting the domestic
economy. Some of the key findings of the report:
- Climate change remains a driving force for
green construction: 77% of respondents stated
that reducing greenhouse gas emissions is an
important reason for their organisation to build
‘green’. In every region, energy savings were the
key environmental reason for green building;
energy is closely related to greenhouse gas
emissions.
- The advantages of green building for society
are on the rise, especially in terms of the health
and wellbeing of users. This emphasises the
importance of people in the built environment.
- Commercial construction remains the strongest
sector for green building, but new residential
construction has also shown steady growth in
green projects since 2015.
119

The international market for green building projects has
grown substantially over the last decade and demand
for green construction work is likely to grow over the
next three years, according to a new report and sector
survey published by Dodge Data & Analytics in 2019.
IWBI brings together a global network of organisations
through IWBI membership, works on relevant research,
develops educational materials and is involved in
policy-making that promotes health and wellbeing
wherever it may be needed.
WELL
People spend around 90% of their lives in buildings
and the conditions and culture inside those buildings
therefore have a major impact on our health. If our
environment is designed with wellbeing in mind, people
in general will feel more comfortable, be more efficient
and perform better.
The WELL Building Standard was launched in October
2014 after six years of research and development. WELL
was developed by combining scientific and medical
research into health, behaviour, health consequences
and demographic risk factors affecting health with best
practices for designing, constructing and managing
buildings. WELL certification is carried out by external
parties, often in conjunction with BREEAM certification
for the building.
The International WELL Building Institute (IWBI)
is now committed to transforming buildings and
communities in ways that will help people’s wellbeing
in buildings. IWBI provides the global rating system
known as the WELL Building Standard, covering how
buildings and everything in them can provide more
comfort, better choices and improved health and
wellbeing in general.
According to the information on IWBI’s website, there
were 35,103 projects underway or completed at the end
of 2021 in a total of 109 countries, involving more than
33 million m2 of construction.
The WELL approach is to focus on the people in the
building. WELL provides a framework for optimising the
health and wellbeing of everyone who works in, visits
or otherwise experiences a building. In a similar way to
LEED or BREEAM, WELL works with various categories
to give an overall final score for the building that is
expressed as Silver, Gold or Platinum.
WELL makes it possible to certify different types of
buildings, such as new buildings, existing buildings and
their furnishings.
WELL is relatively unknown in the Netherlands as yet
but it has been embraced as a standard by the Dutch
Green Building Council (DGBC). This organisation
administers the BREEAM-NL certification. The intention
is to encourage more cooperation between the various
certification bodies.
120

121

122

7
GLASS, FAÇADES AND DYNAMIC SHADING
123

SOLAR RADIATION
The sun produces about 3.85 x 1026 joules of energy per second (W), of which 1.74 x 1017W reaches the
Earth (as measured at the outer limits of the atmosphere). The Earth receives the amount of energy
consumed by humans every year from the sun in less than one hour. The energy reaches the Earth as
radiation at various wavelengths, consisting of UV, visible light and infrared. The atmosphere filters
and reduces the radiation so that only a fraction of it reaches the planet's surface. Infrared radiation at
between 780 and 2500 nm is also called shortwave IR radiation, in contrast to longwave IR (5,000 to
25,000 nm) or thermal infrared radiation, which is emitted by objects in our surroundings.
Radiation that enters a room through glass as
shortwave IR is absorbed inside the room and converted
there into longwave IR that cannot escape from the
room by the same pathway because glass does not
let that type of radiation through. As a result, incident
radiation in the room leads to a temperature increase.
Sun’s angle of incidence
The amount of energy that can pass through window
glass into the room’s interior depends on the angle of
incidence of the radiation onto the glass surface, i.e.
the amount of energy falling directly on the surface.
The underlying causes are the summer and winter
orientations of the sun in relation to the Earth’s poles as
the planet orbits the sun, as well as the time of day as
the Earth revolves around its axis.
In addition to direct radiation, glass surfaces in a
façade also receive diffuse light from the sky and
reflected light from the surroundings (including the
Earth’s surface).
The graphs below show the radiation hitting a vertical
surface on days without cloud cover in summer and
winter. They give a clear impression of the maximum
amount of solar radiation incident on a vertical surface
such as a façade.
Solar radiation on glass
40º Latitude N
December 2021
March 2021
September 2021
June 2021
26.5º
50º
º
73.5º
Source: REVA Solar Shading Handbook
124

Solar radiation incident on vertical surfaces
1000
800
North Facade
21 jun
21 dec
1000
800
East Facade
21 jun
21 dec
W/m 2
600
400
W/m 2
600
400
200
200
0
4 6 8 10 12 14 16 18 20
0
4 6 8 10 12 14 16 18 20
1000
800
South Facade
21 jun
21 dec
1000
800
West Facade
21 jun
21 dec
W/m 2
600
400
W/m 2
600
400
200
200
0
4 6 8 10 12 14 16 18 20
0
4 6 8 10 12 14 16 18 20
Source: REVA Solar Shading Handbook
The preceding graphs clearly show that the radiation on the eastern wall of a building
peaks before noon and the radiation incident on the southern façade reaches its
maximum around noon, whereas the radiation hitting the western wall reaches its
maximum after noon. In winter, the amount of radiation hitting a south-facing side
can in fact be greater than the amount in summer because the sun is lower above the
horizon in winter and therefore shining in more horizontally.
125

Plate glass
Double glazing was developed in the 1960s, followed
by further refinements involving filling the space
between the two panes of glass with gases to optimise
the insulating effect. Ways were also found to colour
the glass or add coatings that could enhance certain
functionalities.
Glass can best be characterised by three parameters:
than the U-value of triple low-e glazing (for which it is
around 0.6 W/m2K).
The differences in the other values between the various
types of glass are much smaller. Other types of double
glazing specifically affect the g-value, for example by
having more heat absorbed or reflected in the outer
layer or by using special coatings that affect the
transmitted spectrum of the incident light.
Thermal transmission (U-value)
The U-value of glass is expressed in W/m2K and it
quantifies the ability of the glass to transmit heat
when there is a temperature difference between outside
and inside.
Light transmission (Tv)
The light transmission value of the glass quantifies the
amount of light that the glass allows to pass through.
The g-value
The g-value says how much of the overall amount of
solar energy passes through and is converted into heat
on the inside. The g-value depends on the angle at
which the sunlight is incident on the surface.
In general, glass allows quite a lot of heat through
(in or out – that was also the reason why demand for
double glazing arose). The space between the two glass
surfaces (whether or not it is filled with gas) provides a
buffer and increases the insulation value of the glass.
Coating the glass with a very thin layer of a metal oxide
(low-e coating) can greatly reduce the U-value. The
U-value of clear single-glazing is about 10 times higher
The glass production process
Glass is made from a mixture of sand, limestone
and soda. These raw materials are heated together
to a temperature of around 1,500 degrees Celsius.
The resulting liquid mass is then allowed to cool in a
controlled way in a furnace. As the liquid leaves the
furnace, an almost infinite ribbon of glass is created.
A computer-controlled system then cuts the glass to
the required dimensions. The panes of glass in various
sizes are sorted at the end of the production line
and put into crates separately to be delivered to the
customer by road.
The insulating effect of a pane of glass
The heat losses in a building are caused by three
major factors:
- Thermal insulation of the structure, including
windows and doors.
- Thermal bridges (also known as ‘cold bridging’).
- Airtightness of cracks and seams.
Thermal insulation is expressed as the energy lost
across a side of the structure when it is 20 degrees
(inside) and the other side of the structure.
126

The value is calculated as the number of watts per m2
per Kelvin (delta T between the inside and out), i.e. W/
m2K. This is also called the U-value.
The lower the U-value, the better the insulation.
In the Netherlands, the inverse is also sometimes
used: the R-value in m2·K/W. The Rc value (for the
whole structure) depends not only on the thickness
of the insulation but also on Rse and Rsi: the
thermal resistance of the exterior and interior of the
structure respectively.
Traditional uncoated double glazing has a U-value of
only 2.6 W/m2K, but coated double glazing has U-values
of between 1.6 and 1.2 W/m2K. The optimum size for the
air gap is 15 to 16 mm. Narrowing or widening the gap
affects the U-value negatively, although a larger cavity
of e.g. 20 mm is better for noise reduction.
Filling the cavity with a noble gas such as argon or
krypton improves the U-value further, to 1.2 or even 0.8
W/m2K. This is because the noble gases insulate better
than just dry air.
As a formula:
Rc =((ΣRm+Rsi+Rse)/1+α) – Rsi – Rse
where Rm = thickness of the material
λ (lambda) = the thermal conductivity coefficient
of the material in W/mK.
Insulating glass was in the past always classified by its
thermal performance into the following classes:
Standard insulating glass .................................... 2.8 W/m2K
HR ............................................... 1.6 > U-value U-value and

When designing a building, there is an unceasing
search for the optimum values, with the percentage of
glass in the façade also a major deciding factor.
If a façade consists of 85% glass, it is better to
lower the U-value and keep the energy transmission
coefficient lower, for example a U-value of 0.6 W/
m2K and a g-value of 40%. A proportion of 35% glass
in a façade – the minimum prescribed in the Building
Decree – needs a U-value of 0.7 W/m2K and a g-value of
57% for the optimum energy effect, though.
The U-value of glass shows how much heat is lost
through the glass alone, i.e. without the heat loss
through the entire outer wall opening, which consists of
the transmission losses through the glass surface plus
losses through the frame (U-glass and U-frame).
The total energy transmission coefficient is also called
the solar factor or g-value. This figure shows the extent to
which the glass blocks (thermal) radiation. Solar-control
glazing reduces the heat gain inside the building, which
can be a solution in the summer in particular. The higher
the solar factor, the more heat from the sun gets in. The
difference between the g-value (used internationally)
and the solar factor (ZTA) is that the latter is measured
at an angle of 45°, whereas the g-value is measured
perpendicularly to the glass.
45º
g-value
90º
The solar factor of a window system is the ratio of
the solar radiant heat flowing in through that window
system to the solar radiation falling on it (NEN 1068;
NEN 7120:11.7.2).
Tables 11.7 and 11.2 of NEN standard 7120 give the
following values:
Window ............................................................ g-value (ZTA)
Clear single glazing ............................................................ 0.80
Clear double glazing or single glazing with a
second pane in front .......................................................... 0.70
Heat-reflecting double glazing, not solar-control ....... 0.60
Various types of solar-control glazing ............. 0.15 to 0.60
Many utility buildings are fitted with glass that insulates
better than standard double glazing. The highefficiency
glass types HR, HR+ and HR++ have a neutral
coating, not specifically for solar control, with high light
transmission. A fixed value of 0.60 for the g-value will
generally be used for these types of glass.
Considerably lower g-values can be achieved for
commercial buildings with solar-control glazing. The
lower the g-value, the more limited the reduction in
energy consumption for heating is, but the higher the
reduction in energy consumption for cooling.
When choosing the type of glazing, it is a question of
finding a balance by looking at both summer and winter.
In summer, it is pleasant to have the heat blocked off,
whereas incoming warmth is desirable in the winter.
ZTA value
Source: www.aaglas.nl
To prevent overheating in the summer, building practice
often aims to keep solar penetration as low as possible
128

Violet
and light penetration as high as possible. The sun’s
heat is then kept out, but daylight can still get in nicely.
Reducing the ZTA value is not the most effective way
of avoiding overheating. Shade created by applying
dynamic or fixed solar shading, overhangs or trees is a
better option for keeping out the heat in summer. These
types of measures let solar heat get into the building
in the winter, which is when we do want to use that
warmth inside as much as possible.
Overheating in buildings can also be prevented by using
the cooler outdoor air at night. The colder outside air is
then allowed in through grilles on the ground floor, with
the warmed air finally escaping through an opening
somewhere high up in the building (night ventilation).
Ingress of light
The light admission factor (LTA), also known as the LT
factor, is the ratio of solar radiation that gets in to the
total incident amount. The higher this factor is, the more
light gets in through the window.
The amount of light that gets in through a window or
façade is affected by the mass of glass, whether or not
an insulating or solar-control coating has been applied,
the presence of a screen print on the glass, applying a
coloured sheet or foil within a laminated glass, use of
dynamic glass (electrochromatic glass) or solar shading
(dynamic or otherwise).
External glass
Direct Energy
Reflection R e
Light admission per type of glass (varying light
transmission factors):
Energy properties of glass
Single glazing (clear float glass) ..................................... 90%
Double glazing (clear float glass with a gap) ............... 82%
Triple glazing (clear float glass with a gap) ................... 74%
Solar-control double glazing ............................................. 61%
The light characteristics only take account of the
visible part of the solar spectrum (from 380 to 780
nm). The light admission factor (or LTA) and the light
reflectivity factor rv (or LR) are the fractions of visible
light that pass through the glazing and are reflected by
it respectively. As the radiation actually absorbed by the
glazing has no visual value, it is usually ignored.
The spectrum of solar radiation
Radiation intensity (amount)
Solar Radiation
Ultraviolet
7%
External radiated
Energy a
Visible
light
Red
44% 37%
Near
infrared
Absoption
Internal glass
11%
Solar Factor
g = T e
+ q i
Direct Energy
Transmission T e
Internal radiated
Energy q i
Source: www.glazingguru.org
Far
infrared
Microwaves
Less than 1%
TV Waves
0.4 0.7 1.0 1.5 0.001
Wavelength (μm)
Wavelength (m)
Source: Iowa State University/Department of Agronomy
129

130

The solar energy that enters a room covers the entire
solar spectrum – in other words, ultraviolet radiation,
visible light and shortwave infrared radiation. That
energy can be restricted without limiting the light by
using glass with an insulating coating that does stop
the UV and IR radiation but not the visible light. That
function of these coated glass products is what we
refer to as ‘selectivity’.
The selectivity of glazing is the ratio of the light
transmission (LTA) to solar factor (ZTA), where
selectivity = LTA ÷ ZTA. The selectivity is always
between 0.00 and 2.33, where zero is opaque glass
with no light transmission and 2.33 is the best possible
selectivity. This is because visible light constitutes 43%
of the solar spectrum’s energy. The closer you get to
2.33, the more selective the glazing is.
Natural light is a significant factor in a healthy indoor
climate and sustainable comfort for living or working.
Glass roofs and large windows in particular let a lot of
daylight and warmth from the sun in. The type of glass
also affects the amount of light that enters. There
are also downsides to using normal glazing; heat and
annoying glare are passed through almost completely
unattenuated. However, to prevent overheating and
annoyance from the sun, the glass can be fitted with
dynamic shading inside or out, fixed awnings or solarcontrol
glazing.
Thermal properties of glazing
The linear thermal expansion coefficient (α) of glass is
8–9∙10-6/K and the thermal conductivity (λ) of glass is
0.8 W/m2 K.
Insulating glazing or double glazing has higher
insulation values due to the enclosed cavity. The
thermal transmission value of glass (the Ugl value) is
largely determined by the thickness of the air cavity
between the two constituent panes of glass. The air in
the cavity must be so dry that condensation cannot
normally occur between the panes. Relatively low Ugl
values can be achieved by filling the cavity with a
special gas (argon or krypton) or mixture.
The NEN 7120 Energy Performance of Buildings (EPG)
standard prescribes an average thermal transmission
of 1.65 W/m2K for all transparent parts together, to be
calculated according to NTA 8800, with a maximum
of 2.2 W/m2K for each individual transparent part. For
active façades, even lower values of 1.2-0.5 W/m2K
should be aimed for.
The U-value of a glazed frame or façade is determined
not only by the U-gl (U for the glass) but also by the U-fr
(U for the frame). U-fr varies roughly between 7.6 and
0.81 W/m2K, depending on the material used for the
window frame. To get the lowest possible U-value, it is
advisable to use as much glass as possible with as few
profile parts as possible.
* In active façades, an outer shell – usually of glass – is placed outside the traditional façade. The cavity between the façade and the outer screen is
in direct contact with the outside air. If the gap is wide, it is referred to as a second-skin façade.
131

Radiation and absorption by the glazing
The solar control effect of glass is quantified as the
ratio between the amount of solar radiation transmitted
(both directly and indirectly) and the total amount of
incident solar radiation.
The quotient of these two quantities is called the
absolute solar factor (ZTA); many publications equate
this to the g-value. In practice, the g-value is always
greater than the solar factor because sunlight that is
perpendicular to the glass is reflected less. The g-value
for glass is determined as per NEN-EN 410.
Light transmission factor
Reducing the amount of solar heat passing in through a
glass opening goes hand in hand with a reduction in the
amount of daylight (visible solar radiation) transmitted.
In many cases, this is a desirable side effect, but
sometimes it is also perceived as an undesirable side
effect. The amount of daylight perceived as being
transmitted depends on the intensity of the incident
radiation, the spectral transmittance of the glazing
(plus blinds if applicable), the spectral sensitivity of the
human eye and the spectral composition of sunlight.
Ingress of light and heat
Light and heat radiation coming from the sun through
the atmosphere to the Earth has wavelengths
expressed in nanometres. Depending on the wavelength
of the radiation, a distinction is usually made between
UV, visible light, shortwave infrared and thermal
radiation (longwave infrared).
Visible light, which has wavelengths of between 380
and 780 nm, consists of the various colours that we
see when light is refracted, for example in a rainbow.
Normally we perceive such light as white. The sun’s
thermal or infrared radiation is shortwave radiation
ranging from visible light to approx. 2500 nm. Infrared
in the longwave region is heat generated by people or
released from objects. Longwave infrared has many
different sources, such as the human body, radiators,
artificial lighting and other heat sources.
Diffuse radiation, for example the light incident on the
northern side of a building, can easily reach 100 W/m2
in the middle of the day. The energy incident on a vertical
façade surface at midday in summer is barely half the
energy shining on the façade on a cold winter’s day.
The last three of these factors determine the amount
of daylight that is perceptible. The absolute light
transmission factor (the Tv value, formerly known
as VLT) is the quotient of the amount of transmitted
daylight and the total amount of incident daylight; it is
a characteristic of the light elimination function of the
sun shading system.
After all, the sun is higher in the sky on average in
summer than in winter. The sun in a summer morning
rises very low in the northeast around 5 o’clock. This
morning sun is not able to make the heat build up
internally and cause overheating.
132

ENERGY
Sun
Short waves
Heating
Long waves
Light
UV
Shortwave infrared
Longwave infrared
280 380 780 1000 2000 2480 3000 50.000
Wavelength in nm
Source: staka-dakluiken.nl
Direct radiation in summer
1000
Direct radiation in winter
Intensity of solar radiation(W/m2)
800
600
400
200
East-facing façade
in summer
East-facing
façade
in winter
Flat roof
in summer
South-facing
façade in winter
South-facing
façade in summer
Diffuse radiaton
in summer
West-facing
façade
in winter
Diffuse radiation
West-facing façade
in summer
0
4
Diffuse radiation
in winter
6 8 10 12 14 16 18 20
Hour of day (h)
Source: agcnederland.nl
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Insulation by glass
Until about the 1980s, not much could be done about
the glass. At that time, we did already have solar
control glass that was simply tinted right through, thus
absorbing the heat. After that, people started using
wafer-thin coatings involving a metal oxide layer,
applied to the hot glass as it comes out of the furnace,
that reflects both light and thermal radiation. Solutions
like these do reduce the solar heat gain, but at the
same time eliminate a lot of light.
In non-residential construction, summer conditions are
also considered so as to reduce the use of cooling in
summer; the aim is to optimise energy consumption
and avoid productivity losses. Such considerations are
particularly important in non-residential construction
because entire façades are often made of glass
there and the glass therefore largely determines the
optimisation of the indoor climate. The cooling capacity
required is then largely determined by the solar control
properties of the glass. In the ideal case, a building
is optimised so that the indoor temperature does not
exceed 23°C in the summer.
There is an increased risk of errors in this respect as
average temperatures outdoors are rising sharply due
to climate change and the temperature taken into
account can be an underestimate. There are examples
of cities where the outside temperature in recent
years has averaged 5°C higher than the figure used in
calculations. It may also be the case that the glazing
does not achieve the assumed solar control properties.
Window panes actually have very poor insulating
properties, as glass has a high emission value as
well as a high heat transmission. Single glazing still
provides some insulation because there is a layer of
air on either side of the pane that insulates (known as
the transition resistance).
As a result of the EPC standard in the Building Decree,
HR++ window panes are often used in residential
construction. The glazing used has thermal protection
properties but no solar-control properties.
Modern European types of solar-control glass take both
winter and summer situations into account. That is why
window panes are made with solar control properties
and a good insulation value of around U=1.0 W/m2 K. To
assess the actual insulating value of glazing, you have
to look at not only the loss of heat through the pane
(U-value) but also the energy increase in the interior
through the pane, known as the g-value. The energy
transmitted through the window is expressed as an
equivalent U-value, where Ueq = U-value – (g-value × f).
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The desired temperature
A study by Prof. Hauser from Kassei shows that the
desired indoor temperature is often not maintained in
summer and that the indoor temperature is too high for
a considerable number of hours a year, despite the use
of solar control glazing. The graphic below shows the
results of his research. The study was carried out using:
- heat-reflecting glass with a g-value of 60% and
adjustable blinds;
- solar control glass with a g-value of 40% and
switchable glass.
ensuring good contact with the outside when the sun
protection is closed or lowered. It is determined by two
parameters: the normal transmission of light and the
diffuse component of the light transmitted.
Privacy
Privacy is the opposite of visibility; it is about the
view from the outside to the inside. Privacy is a
classification to determine or guarantee the level
of transparency in the inward direction with the sun
protection closed or lowered.
The measurements show that solar control glass
is actually not enough to keep excessively high
temperatures below the maximum of 500 hours a year.
Heat classification as per NEN-EN 14501
As well as the heat burden, light ingress (visual
comfort), transparency, privacy and glare all play a role
in creating a good working environment.
Visibility
Summer situation
Overshoot temperature degree hours °h x (kH/a)
2000h
1500h
1000h
500h
0h
323 Kh 575 Kh 1167 Kh 2062 Kh
Heat-reflecting glass g-value
60% + adjustable horizontal blinds
Solar control glass
g-value 40% static
Source: staka-dakluiken.nl
Façade orientation: east
Night ventilation: n = 2/h, without cooling
70% glass surface 90% glass surface
Switchable glass
Temperature control in room
from 21°C is lowered
Visibility means how well you can see from the inside to
the outside. The view or visibility is a classification for
86 Kh
144 Kh
Admissible future requirement value
according to DIN 4108-2
Glare
Glare is about the reflections of sunlight: in other
words, it is a classification for the amount of reflected
light at the workplace when the solar shades are
closed or lowered. Pale-coloured fabrics will diffuse
(‘scatter’) more light into the room than darker colours.
You therefore have to weigh up what is perceived as
pleasant or comfortable, a pale surface with less
contact with the outside or a dark surface with various
points of light (resulting in direct glare) and better
contact with the outside.
Class 2 is sufficient for optimum working conditions with
computer screens. Classes 3 and 4 progressively darken
the room more and artificial lighting is often needed.
These aspects are categorised in classes according
to the NEN-EN 14501 standard. More generally, that
standard classifies the thermal and visual properties of
heat and light controls as follows:
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136

Energy flows
Schematic representation of the main energy flows
in a window opening plus outside blinds
Convection
Absorption
Secondary
long wave
radiation
Directly
transmitted
short wave
radiation
Shade
Source: REHVA Solar Shading Guide Book
When incident light hits a surface, there is always absorption, transmission and reflection.
Absorption increases the surface temperature of both fabric (in the shading) and glass (in
the window) and shorter wavelengths are also partly converted into longwave radiation:
in other words, some of the energy is also released into the surroundings. Any mass of
stationary gas or stationary air has an insulating effect; therefore so does the air mass
between the fabric of the dynamic shading and the glass surface.
Schematic representation of the main energy flows
in a window opening plus inside blinds
Convection
Convection
Secondary
long wave
radiation
Absorption
Directly
transmitted
short wave
radiation
Reflection
Source: REHVA Solar Shading Guide Book
137

When using dynamic shading indoors, the entire amount
of solar energy falls on the window first, so that a large
proportion of the energy has in fact already got inside
and stays inside (except the fraction that reflects off
the outer surface of the fabric used in the internal
shading). The fabrics used in most cases are textiles,
as they are for outdoor shading. The energy that enters
the room is given off to the surroundings and a small
proportion of it disappears again through the window.
This is because the stationary air between the fabric and
the window warms up, passing heat on to the glass; the
glass will then partially transmit that heat to the outside
because of temperature differences between the inside
and outside (depending on the U-value of the glass).
Within the system as a whole, this outgoing heat flow is
relatively small. In fact, two factors are at play here as
well as the transmission: reflection at the back of the
fabric and the absorption of energy by the fabric itself.
The glass surface temperature, especially of the pane
on the inner side of double glazing under maximum
burden without shading on the outside, ranges from
35 to 40 degrees Celsius in Amsterdam. In all cases,
the maximum values are achieved with low-e glazing
compared to ordinary double glazing and special solarcontrol
glass.
Using sun blinds outside reduces that surface
temperature by between 5 and 10 degrees Celsius,
keeping the figures below 32 degrees Celsius (again
measured under peak burden). This has a favourable
effect on the indoor temperature in the summer, in
the winter, under certain circumstances, it has the
opposite effect.
In general, higher glass surface temperatures will
increase the functional temperature inside, affecting
thermal comfort.
The energy demand resulting from artificial lighting
use in an office building with traditional lighting can
quickly reach 40% of the total energy consumption
of the building (with traditional lighting, that is; it
is significantly less with modern LED lighting). Sun
shading reduces the incident radiation and therefore
the incident light. It is perhaps worth considering
whether the reduction in cooling costs by using blinds
would outweigh the additional cost of lighting due to
increased demand. Lund University carried out research
into this in 2007, reaching the conclusion (in this case)
that internal blinds combined with low-e glazing did
not require artificial lighting to be switched on while the
blinds were in use, as the light values measured did not
fall below the minimum required level.
Energy effects of solar shades
As the results depend partly on the geographical
location, we are limiting the conclusions here to the
situation in the Netherlands. For a typical office in
Amsterdam, the cooling and heating needs are roughly
balanced:
- Solar heating in the winter means that the
need for heating on south-facing façades is
significantly less than on north-facing ones. On
the other hand, there is a significant need for
cooling in summer, with the associated energy
consumption.
- In general, the energy demand of an office that
has dynamic shading on the façade is lower in
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summer than for an office without such shading.
However, the effectiveness of dynamic shading
depends heavily on the orientation of the façade
to the sun. Measured on the south façade,
applying dynamic shading saves about 40-50%
of the energy for heating, cooling and lighting.
- Under the same conditions, similar savings
can also be achieved on east-facing and westfacing
façades.
The cooling burden as a function of façade orientation
W/m2
200
150
100
Visual comfort
Inside a building, there is usually a mix of daylight
and artificial light during the day. The amount of
daylight depends on the time of day, season, weather
conditions, window dimensions and any measures
taken to regulate incoming light. Another issue is the
reflection of light off surfaces; this can disrupt visual
comfort a lot.
A good rule of thumb for visual comfort is the 1:3:10
rule, which says that good daytime visual comfort
needs the amount of light in the centre of the field of
vision (computer screen) to be about 1/3 of the amount
of light in the workplace with the surroundings being no
more than 3 times brighter.
50
0
north
Source: REHVA Solar Shading Guide Book
The solid lines in the graph represent the cooling load
with no sun shading applied and the dashed lines are
the cooling burden when dynamic sun shading is used.
Thermal comfort
east south west
Thermal sensations as perceived by the human body
depend on the air temperature and the temperature
of the surrounding objects; the combined effect is
called the operative temperature. The amount of
incident sunlight obviously influences thermal comfort.
This influence is greatest near the window and the
temperature in a room can therefore easily vary several
degrees, depending on where it is measured.
Simulations during the design phase of a building
can help make predictions about light incidence and
temperature. All kinds of variables play a part in this. An
indirect consequence of the incidence of light is that it
also affects the air quality in the building.
Thermal effects can affect the air quality in a building.
Incoming solar radiation not only raises the temperature
inside the building but also increases the temperature of
the glass surface and of the rest of the building envelope.
In this sense, using dynamic shading influences the
temperature, light incidence and air quality.
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Ingress of sunlight and other radiation for
various types of shading
Retractable awnings
The g-value was calculated by TNO Bouw and recorded
in report B-92-0268 of 16 March 1992. The following
assumptions were made for the calculation:
- The sun’s elevation was at an angle of 45°,
directly in front of the screen.
- The wind speed was set to 1 m/s.
- The outdoor temperature was 5°C and the indoor
temperature was 20°C.
- The distance from the screen to the façade is 50
mm with free ventilation.
The g-value depends largely on the colour of the
textile. Green and blue have low transmissivity,
whereas the figure is much higher for white and
yellow. The reverse is true for absorption, but the
reflection value hardly varies.
Bartenbach Lichtlabor Prüfinstitut in Innsbruck.
The assumptions made for this were:
- Full sun shading.
- Distance from the shading to the façade of
50 mm with free ventilation.
- Wind speed 1 m/s.
- Slat orientation optimal for the position
of the sun.
The g-value depends on the slat shape and (to a limited
extent) on the slat colour, ranging between 0.04 and
0.19. For this type of blind, the ingress of light can be
regulated as required.
Dark-coloured slats reduce light reflection. Systems
have been developed in which it is possible to vary the
orientation of the uppermost slats with respect to the
others, allowing additional daylight into the room (this is
also known as ‘daylight transport’). This allows savings
on the cost of using lighting.
At higher wind speeds, the g-value will drop further; it
will increase when the sun is at an angle to the façade
and at lower sun elevations in the sky.
Screens
The g-value here was also calculated by TNO Bouw,
with the same assumptions as for retractable
awnings. The calculation was based on double glazing,
4/12/4-EN 14501.
Brise soleil systems, horizontal and vertical
As far as we are aware, no general calculations have
been done for these types of shading. The systems are
so specific that a calculation would have to be made for
each individual project. The g-value of fixed brise soleil
systems that extend horizontally depends on how far
they protrude and the orientation of the slats. After all,
the lower the elevation of the sun, the more direct solar
radiation there will be onto the glass.
Venetian blinds on the outside
The g-value has been calculated by e.g. the Fraunhofer
Institute for Solar Energy Systems in Freiburg and the
Movable or dynamic systems in particular will be able
to achieve favourable g-values because the amount of
light getting in can then be adjusted as required.
140

Noise
Although it may not seem obvious, noise is also an
aspect that plays a role when dynamic sun shading
is applied.
Wind noise
Resonance or other noises generated by the wind can
occur in practice. This depends heavily on the specific
architectural details, the substrate that the shading
is fitted to, the dimensions and the wind forces on
the façade.
Motion sounds
When the solar protection is moving, sounds can be
heard that are related to the drive, friction between
moving parts or the sounds of springs used in the arms
of retractable awnings.
An awning often has a cassette to protect the retracted
fabric, which can amplify sounds. Amplification of the
sounds can also occur in recesses where the blinds are
placed or in the form of contact noises due to the way
the shades have been hung.
141

142

8
PROPERTIES OF TECHNICAL FABRICS
IN DYNAMIC SHADING SYSTEMS
143

COMMONLY USED MATERIALS
Polyester
Polyester is a synthetic fabric made from petroleum. It is one of the world’s most popular
types of fabric and it is used in thousands of different consumer and industrial applications.
Chemically, polyester is a polymer that consists of a chain of molecules linked together by
ester functional groups.
W.H. Carothers (at DuPont) discovered that certain
alcohols and carboxylic acids could be successfully
mixed to create fibres. It was two British scientists,
Whinfield and Dickson, who patented the discovery
in 1941. Polyesters include synthetic fibres such as
Dacron (Terylene), which is based on polyethylene
terephthalate. Later in 1941, the first polyester fibre,
Terylene, was made by Whinfield and Dickson, together
with Birtwhistle and Ritchiethey.
Terylene was first produced by ICI (Imperial Chemical
Industries). DuPont bought all the rights from ICI in
1946. In 1950, DuPont produced a polyester fibre that
they called Dacron. Mylar was introduced in 1952.
Polyester was first introduced to the American public
in 1951, as the magic fabric that does not have to
be ironed. PET (polyethylene terephthalate) and PEN
(polyethylene naphthalate) are variants that improve
certain characteristics. Both are trademarks of DuPont
as variations on polyethylene.
The polyester market expanded rapidly after the Second
World War and textile factories started appearing all
over America. The cheap and durable fibre quickly
became popular and the industry rapidly expanded until
the 1970s. Nowadays, polyester is considered a cheap
fabric for clothing that is rather uncomfortable to wear
for people with sensitive skin.
With the rise of luxury fibres such as polyester
microfibres and various other polyester mixes, polyester
experienced another upsurge later on. The idea was to
start focusing more on the wash-and-go properties of
polyester instead of marketing it as a cheap fabric.
Hoechst Fibers Industries also played a role. They did
various studies from 1981 to 1983 and discovered that
89% of people could not distinguish between polyester
and other (natural) fibres such as cotton, wool and silk.
People also appeared to be more interested in what the
clothing looked like than the fabric it was made from.
The discovery of microfibres boosted the appeal of
polyester. Microfibres make polyester feel like silk.
Polyester is a term often defined as “long-chain
polymers chemically composed of at least 85%
by weight of an ester and a dihydric alcohol and a
terephthalic acid”. It means that lots of molecules are
linked together as esters to make fibres. The reaction of
alcohols with carboxylic acids produces esters.
Polyesters can also be classified as saturated and
unsaturated. Saturated polyesters refer to the family of
polyesters in which the polyester backbone is saturated.
They consist of liquids of low molecular weight that are
used as plasticisers. Unsaturated polyesters are those
polyesters in which the backbone contains double
144

onds that are typical of e.g. alkyl thermosetting resins.
These are mostly used in reinforced plastics.
Due to its strength, polyester is also used to make ropes
and cords. PET bottles are now one of the most popular
uses of polyesters.
Polyester fabrics and fibres are extremely strong,
durable and resistant not only to most chemicals but
also to stretching and shrinking, wrinkles, mildew and
wear and tear. Polyester is quick-drying and can be
used for insulation when hollow fibres are produced.
Polyester keeps its shape and is therefore suitable
for making outdoor clothing for use in very cold or wet
climates. Polyester clothing is easy to wash and dry.
Polyester is a naturally transparent fibre. During
production, polyester fibres are generally stretched
to about five times their original length. Stretching
them even further makes them thinner: they become
microfibres. Normal polyester fibre are long and
smooth. Crimping the fibre can give it more volume
and texture, improving its insulation capacity. When
the polyester fibre is ready, it is used to make spun
yarns. The yarns can be mixed with other fibres to
make mixed fabrics. One popular combination is
polyester and cotton.
Trevira CS
Trevira CS is a flame-retardant polyester produced by
Trevira GmbH. They process the material into textile
polyester products, including yarns (fibre, flat, filament
and textured) for household textiles and functional
clothing, as well as for technical textiles and hygiene
products. The company’s specialities are fibres and
yarns for flame-retardant technical textile fabrics
(the Trevira CS brand) and textiles with a permanent
antimicrobial effect (the Trevira Bioactive brand).
Since 2019, all recycled Trevira products are certified by
Control Union according to the GRS norm.
PVC fabrics (polyvinyl chloride)
Vinyl chloride or chloroethylene (the IUPAC name)
is a chlorinated organic compound with the formula
C2H3Cl. This substance is a colourless gas that
dissolves poorly in water.
Strangely, its history begins in two separate years
(1838 and 1872) when the French physicist Henri
Victor Regnault and the German chemist Eugen
Baumann discovered PVC for the first and second
times respectively. On both occasions, the polymer
materialised as a “white solid” (in the form of a powder)
in flasks filled with vinyl chloride gas.
Global production of PET was 30 million tons in 2000.
Production of PET textiles is increasing by 5% per
year and production of PET bottles is going up by 10%
annually. China produces the most polyester.
145

After these independent discoveries, nobody controlled
the use of PVC in commercial applications until 1913,
when a German inventor called Friedrich Heinrich
August Klatte decided to patent the substance. His
polymerisation method for vinyl chloride used sunlight
and companies all over the world started experimenting
in the subsequent decades.
Shortly after the turn of the previous century, B.F. Goodrich
hired the industrial scientist Waldo Semon to develop
a new, synthetic alternative for natural rubber, which
was becoming increasingly expensive. Experiments
were started with polyvinyl chloride, but the project was
quickly threatened by the 1920 recession.
After the idea arose to use PVC as a water-resistant
coating for fabrics, sales of the material took off, with
peak demand at the start of the Second World War when
PVC was used as insulation for wiring, including on
military vessels.
By around the 1950s, production of PVC was increasing
all over the world. Five companies in particular started
testing revolutionary uses for PVC and found new
applications for the substance in inflatable structures
and fabric coatings. The construction industry quickly
welcomed this durable plastic, largely due to its
resistance to light, chemicals and corrosion, making it
an important product in construction.
Further improvements were made to the temperature
resistance of PVC in the 1980s. Around the same time,
people started using the material in sanitary systems
in thousands of American homes. Today, we can find
the material in many sectors, including healthcare, IT,
transport, textiles and construction.
PVC is produced by polymerisation of vinyl chloride
monomer (VCM). Polymerisation is a process in which
relatively small molecules, called monomers, are
chemically combined to produce very large chain-like or
networked molecules called polymers.
About 80% of the production is done through
suspension polymerisation. The raw material VCM
is first compressed and liquefied and then fed into
the polymerisation reactor, which already contains
water and suspension agents. PVC is formed as small
particles that grow and when they reach a desired size,
the reaction is stopped and all the unreacted vinyl
chloride is distilled and reused. The PVC is separated
and dried into a white powder.
In a different process, fibres are pulled from a mass
of wadding and spun into threads; this turns the fibres
into a yarn. Spinning can be done by hand but is done
at a large scale using machines. Spinning PVC is the
process that turns the material into a fibre.
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147

To turn a polymer into a fibre, the polymer has to be
liquefied, which can be done in dry or wet spinning. In
the dry spinning process, the polymer is dissolved using
acetone, filtered and pumped by spinning mills at 70 to
100 degrees in a chamber that has heated walls that
air is fed into. The fibres are removed at the bottom
of the chamber through a fine aperture and wrapped
around a spool. The fibres are then stretched to ensure
the molecular chains become aligned, which makes
the fibres stronger. In the wet spinning process, PVC is
dissolved in THF (tetrahydrofuran) to produce a highly
concentrated solution that is spun into water through a
rotating funnel.
Specific characteristics of PVC fibre:
- Contracts at temperatures above 78°C and
shrinks into half its original length at 100°C.
- Excellent resistance to sunlight.
- Very resistant to insects and microorganisms.
- Non-flammable.
- Exceptionally resistant to caustic soda, nitric
acid, sulphuric acid and many other chemicals
including bleaches.
water and chemical resistance, lifespan and because
producing these fabrics demands less energy than
most other types of industrial textiles. PVC has an
amorphous structure containing halogens such as
chlorine and fluorine, and it is known to be stable.
This chemical stability is what makes PVC resistant
to flames, chemicals and oils. PVC vinyl textiles are
suitable for a wide range of applications, such as:
- Protective suits for astronauts, firefighters and
military personnel.
- Industrial tarpaulins, hydraulic hoses, conveyor
belts, geomembranes, bags and containers.
- Automotive applications such as airbags, seat
covers, roof liners, convertible car tops.
- Aerospace applications such as hot air balloons,
airships, space landing airbags and parachutes.
- Marine applications such as covers for boats,
sails, life jackets and hovercraft skirts.
- Architectural and structural applications such as
roofing, canopies and inflatable structures.
- Fabrics for healthcare, including fire-resistant
mattresses and antimicrobial privacy curtains.
Weaving is a method of textile production where two
different sets of yarns or threads are woven at right
angles to each other to create a fabric or cloth. The
longitudinal threads are called the warp while the lateral
threads are called the weft.
PVC vinyl textiles are synthetic technical fabrics that
are strong, durable and flexible. They are resistant to
wear and tear and deformation. Many manufacturers
favour PVC fabrics due to their ease of use, versatility,
148

PVC-coated fabrics are popular for architectural
applications. Architectural PVC-coated fabrics are
usually made by applying a liquid PVC coating. Vinyl
and PVC can be easily mistaken for one another,
but these two materials are not the same. Vinyls are
petrochemical products made from various ethylenebased
monomers and PVC is polyvinyl chloride, the
polymer made from vinyl chloride.
DuPont developed a suitable resin for combining
the fibreglass with a plastic to produce a composite
fabric in 1936. After the war, the substance became
known more as a building material. Many fibreglass
composites continued to be referred to as ‘fibreglass’
(as a generic name) and the name was also used for
the glass wool product with low density containing gas
instead of plastic.
Native polyvinyl chloride has very poor heat stability.
For this reason, additives that stabilise the material
at higher temperatures are usually added to it during
production. Polyvinyl chloride emits toxic vapours
when it is melted or exposed to fire. Most woven vinyl
fabrics start with polyester yarn as the core which is
then extruded with PVC. The PVC coating means that
moisture cannot get to the polyester fibre, making it
extremely durable.
Fibreglass
Woven fibreglass textile is an inorganic composite
fabric consisting of glass strands of various sizes. All
fibreglass fabrics are woven for fibre orientation and
each fabric has its own unique weight, strength and
fabric properties. The earliest patent was awarded to
the Prussian inventor Hermann Hammesfahr (1845-
1914) in the United States in 1880. Mass production
of glass strands was accidentally discovered in 1932
when Games Slayter, a researcher at Owens in Illinois,
aimed a jet of compressed air at a stream of melted
glass which then produced fibres. Fibreglass was
originally a glass wool with fibres that contain a lot of
gas, making them useful as an insulator, especially at
high temperatures.
The process of producing fibreglass is called pultrusion
(pulling and extrusion). The production process for
fibreglass suitable for reinforcement uses large ovens
to gradually melt sand and other minerals until they
form a liquid. This liquid is then extruded through dies
containing lots of very small openings.
These fibres are then coated with a chemical solution
and then bundled in large numbers. These bundles
are then used directly in a composite application. The
term fibreglass refers to a group of products made
from individual glass fibres combined in various forms.
Glass fibres can be categorised into two large groups
based on their geometry: the continuous fibres used in
yarns and textiles, and the discontinuous (short) fibres
used for sheets or plates for insulation and filtration.
Fibreglass can be made into yarns, just like wool or
cotton, and woven into a fabric.
A long, continuous thread can be produced by rolling
multiple strands onto a fast winder after the glass flows
through the holes in the die. The winder runs at about 2
miles (3 km) per minute, which is much faster than the
flow speed of the die. The tension pulls on the thread
while it is still molten, drawing it into strands that are
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150

just a fraction of the diameter of the openings in the die.
A chemical binding agent is added to help prevent the
fibre from breaking during later processing. The glowing
thread is then spun onto tubes.
Fibreglass yarns are usually covered with a PVC coating.
Fibreglass cloth is mechanically highly resistant (to
breaking and tearing) and can be placed under tension
without getting deformed to create contours and
volumes. The material does not deform when exposed
to heat, barely shrinks and keeps its colours when
exposed to sunlight (high UV resistance).
The g-value and U-value
The g-value is a measure of the amount of solar
heat (infrared radiation) allowed to pass through a
certain part of a building. A low g-value means that a
window/fabric only allows a low percentage of solar
heat to pass through.
The U-value is a measure of the amount of heat
that escapes through windows, walls and the roof.
The U-value is often measured for the entire window
structure, i.e. the combination of glass plus window
frame. The lower the U-value, the better the window
is insulated.
In a normal residential building, there is estimated to
be an average of 25 to 30 m2 window glass. Housing
normally uses insulated glass with U-values of between
1.2 and 1.6. Theoretically, a difference of 0.1 unit in
U-value is equivalent to energy consumption of about
9 kWh per m2 of glass per year. The difference between
1.6 and 1.2 is 0.4 units, which saves (the difference in
U-value) x (additional consumption) x (glass surface
area) = 4 x 9 kWh/m2 x 30 m2 = 1,080 kWh/year.
European standard EN 14501
Thermal and optical values such as those defined in the
European standard EN 14501 (for blinds and shutters,
thermal and visual comfort, performance parameters
and classification) are used to measure the solarcontrol
properties of a fabric or textile. The standard
is based on several criteria and defines various
classifications for comfort.
The solar factor is used for thermal comfort, and visual
comfort refers to opacity: privacy at night, the view to
the outside as well as reflecting and using natural light.
There are five levels of performance classification:
0 very little effect
1 small effect
2 moderate effect
3 good effect
4 excellent effect
EN 14501 defines the total solar factor g tot
(fabric
used for sun protection + flat glass in the window
frame) as the most important property for thermal
comfort and the tv-value as the most important
property for visual comfort.
151

Two standards are used for calculating the total
solar factor:
NL13363-1
This standard is a simplified method that calculates
the estimated values for the total energy transmittance
(g tot
) of glazing and sun shading combined. Inputs for
this calculation are the optical and thermal parameters
of the glazing and sun shading. The calculation process
can easily be done in a spreadsheet. The results of this
calculation are generally higher (by up to 0.1) than the
precise values from EN 13363-2.
Thermal comfort
The solar factor determines the percentage of solar
energy entering a space through sun protection and
glazing; it is expressed as an index from 0 to 1. The
closer the index of the fabric gets to 0, the more
efficient it is in terms of protecting against heat.
NL13363-2
The detailed calculation method calculates more
accurate values for the total solar factor (g tot
) of
glazing and sun shading combined. This calculation
is based on the spectral transmission and reflection
parameters of the sun shading and glazing.
The calculation requires specialised software for
solving the non-linear system of equations. The
results of calculations according to EN 13363-2
are suitable as input for cooling load calculations.
Radiation from the sun always partially passes
through, is absorbed by or is reflected by the fabric.
The sum of all three is 100% of the energy from the
sun that is incident on the surface area.
In general, external (in particular dynamic) sun
protection provides better thermal protection than sun
protection on the inside because the solar radiation,
which is partially absorbed by the fabric before it
reaches the glazing (As), is reflected outside.
Dark colours protect better against heat than pale
colours because they absorb more solar energy (have a
lower value of Ts).
Ts + Rs + As = 100% of the solar energy.
Conversely, pale colours are more efficient when used
indoors. They absorb less heat (a lower value of As) and
reflect light more (higher Rs) than darker colours.
152

Factors that determine
thermal comfort
Translucency
The proportion of the light energy that passes through
the fabric. A low percentage means that the fabric
performs well in lowering the temperature.
Reflection
Rs
Rs
Ts
Ts
Ts
Total solar factor (g tot
)
The total solar factor indicates the proportion of the
energy that actually penetrates OF through the sun
protection and glazing into the space behind. A low
value means good thermal performance. The solar
factor has been determined for four standardised
glazing types as defined in Appendix A of EN 14501. The
basic glazing is type C (thermal transmission factor of
the glazing merely U = 1.2 W/m2K, solar factor of the
glazing only gv = 0.59).
The impact of heating and air conditioning systems
of buildings on both the environment and the climate
is considerable: they represent 30 to 40% of the
emissions of carbon dioxide and other greenhouse
gases. Improving the thermal performance of buildings
is vitally important for achieving the Paris Agreement
objectives and complying with both international and
Tv
local regulations.
Tv
OF
OF
Rv
Rv
Rv
Rs
The proportion of the solar radiation that is reflected
by the fabric. A high percentage means that the fabric
performs well in reflecting solar energy.
Heat absorption
As
As
As
The proportion of the solar radiation absorbed by the
fabric. A low percentage means that the fabric does not
absorb much energy.
Technical fabrics used for shading have two effects:
Tv
on energy consumption by reducing the use of heating
and air conditioning and on comfort and the wellbeing
of people in buildings by controlling the light and
temperature in the winter and summer.
T&F
T&F
There is a wide selection of fabrics with various
openness factors and colours that can be used to
T&F
control how much daylight is allowed to pass through.
The amount of available daylight also determines the
amount of artificial light needed.
153

Depending on the orientation of the façades of a
building and the use of space, the light needs to be
filtered to some extent to prevent glare. The denser
Ts
and darker the fabric, the more effectively the glare is
controlled. Conversely, pale fabrics should be selected
if you want to promote light penetration, as well as
fabric with a high degree of openness.
Using natural light improves the energy performance of
a building, as well as enhancing the well-being of the
users and raising productivity.
Ts
Ts
Openness of the fabric (Tvnn)
OF OF
OF
This is about the gaps in the fabric structure; it is a
factor that is independent of the colour.
Translucency (Tvnh)
Emissivity
The emissivity of a material is the ability to retransmit
the energy acquired by conduction (heat or cold). When
used indoors, fabrics with low emissivity will limit the
effect of internal radiation. The energy emitted by this
reflection remains indoors, reducing the consumption
Rs
Rs
of energy for heating.
Visual comfort
Dark colours provide better transparency and give more
opportunities for avoiding glare. On the other hand,
paler colours in particular spread more natural light.
Rs
As
Rv
Rv
Tv
Rv
Tv
The factor refers to the total percentage of radiant
Tv
light passing through the textile over the range of
wavelengths from 380 to 780 nm (nanometres), i.e.
the visible spectrum.
Light reflection (Rvnh)
T&F
T&F
As
T&F
As
This is the proportion of light that is reflected by
the fabric.
154

Natural light is an important factor for our well-being.
Natural light regulates various endocrine functions
and regulates sleep and the body’s water balance.
It improves employees’ perceptions of their working
conditions. Depending on the circumstances, however,
you might need more or less natural light, or even need
to prevent it from getting into a space.
The level of light varies depending on the openness of
the textile. The more open the cloth is, the more light
passes through. The translucency depends partially on
the colour and determines the brightness or shine.
Dazzling
Natural light must be properly managed to prevent
dazzling. Glare is a source of eye strain, especially glare
off computer screens. Just like heat, visual comfort
helps ensure employees are efficient while they are at
work. Factors that make it possible to control glare are
the openness of the textile and its translucency.
The choice of fabric also depends on the geolocation
and layout of buildings. Solar control textiles make it
possible to regulate the luminance level of the window
(the natural light spread throughout the room) as well
as reducing disruptive contrasts between light and dark
within the field of view. Depending on the colour, solar
control textiles can become a light source if sunlight
falls directly on them.
Transparency of solar control fabrics
A view to the outside lets you keep track of time and
space, and is essential for your mental balance. It
reduces stress and helps improve productivity.
One determining factor is the openness of the textile
used. Darker colours facilitate transparency. For
maximum transparency, the openness factor should be
higher than 5%.
On the other hand (when it comes to privacy – and
especially if a building is illuminated from inside at
night), it is preferable to pick opaque awning textiles.
Heat management
Awnings are important in façades thanks to their
influence on energy consumption, linked to the use of
air conditioning and heating in the buildings.
Summer comfort
Fabrics for exterior solar control offer better thermal
protection because the solar radiation – which is
partially absorbed (As) by the fabric before it reaches
the glazing – is reflected back outside. Dark colours
protect better against heat than pale colours because
they absorb more solar energy (a lower value of Ts).
The luminance level of surfaces is measured according
to the norm NF X 35-103. Acceptable values are
between 16 and 150 Cd/m2. A sheet of paper is about
100 Cd/m2.
155

Conversely, pale colours are more efficient when used
indoors. They absorb less heat (lower As) and reflect
more light (Rs) than darker colours. Moreover, fabrics
with a low emissivity reduce the perception of heat
emitted through the windows.
In the summer, awning fabrics improve energy savings
by reducing the use of cooling systems and air
conditioning.
Winter comfort
Awning fabrics have an insulating effect on glass and
help reduce heat loss at night, while at the same time
helping combat the cooling effect of glass during the
day. Using indoor solar protection to control brightness
affects energy consumption because the net-zero cost
effect of the sun is partially retained. In the winter,
awning fabrics help save energy on heating.
Impact of awning fabric colours
There are four important aspects to consider when
picking a fabric.
Translucency (Tv%)
Translucency refers to the proportion of visible light
passing through the textile. Generally, darker colours
have lower values than paler colours. Fabrics with
an openness factor of over 3% let large amounts of
visible light pass through the fabric. A Tv value of 7%
is reckoned to be the maximum level of visible light
transmission for schools and offices, for example.
The following three factors are taken together and
are about what happens to all the energy: it is about
the combination of light and heat. The combined
percentages always add up to 100%.
Absorption (As%)
Light absorption means the amount of solar energy
absorbed by the fabric. It is well known that dark
colours absorb more solar energy than paler fabrics
and will therefore have a higher As% value. If heat
accumulation is a problem, people select a paler fabric
or a dark one with a reflective backing for indoor use.
Reflection (Rs%)
The reflection indicates how much solar energy the
fabric reflects. A high value means that the fabric
performs well in reflecting solar energy back outside.
Fabrics with reflective metallised backings generally
have the best reflection values.
Transmission (Ts%)
The light transmission indicates the percentage of
solar energy that is passed through the fabric to the
environment. A low Ts% value means that the fabric
performs well in reducing the amount of solar energy
entering the building through the glass. Dark colours
have lower Ts% values than paler colours because they
block more light.
156

There is often a conflict between reducing heat (pale
colours preferable) and reducing light (dark colours
preferable). That is why best-of-both-worlds grey
shades are often used as awning textiles in nonresidential
buildings.
The ultimate compromise is often to select a fabric
for indoor use with a highly reflective backing. The
metallised layer faces the glass and gives a high Rs%
value. At the same time, this backing creates a solid
coating over the threads of the fabric, considerably
reducing the light scattered by the yarns. This also
achieves a low translucency (Ts%), irrespective of the
fabric colour. There are fabrics that reflect 82% and
absorb 15% of the light, i.e. only allowing 3% of the solar
energy to pass through the textile into the building.
Selecting the right type of textile
for use in awnings
In general, when selecting the best fabric for awnings
it is important to know what the effect of a specific
colour is. So in addition to a textile’s primary technical
properties, the colour of the fabric also has an effect,
although that is limited to a few percentage points.
Awning fabrics are often selected for the colour and
style that best fit the interior. Unfortunately, this
aesthetic approach does not take account of the
fabric’s ability to control dazzling, allow a view out, allow
diffuse daylight into the space, or reduce solar heat
gain. If colour is the key consideration when selecting
a fabric, people are more likely to pick textiles that look
good on the wall or the façade, but possibly do not give
satisfactory daylight performance.
The openness factor (OF) of a textile refers to the
amount of light that can pass through the fabric
unhindered. An openness factor of 5% means that 5% of
the sunlight passes through at an angle perpendicular
to the glazing. The remaining 95% of light is diffused,
reflected or absorbed.
Visible translucency (Tv) refers to the total amount of
light and includes both direct and diffuse light. The Tv
value of a colour is mainly influenced by the physical
gaps in the texture and the colour of the fabric’s yarn,
but it is also affected by the shape and specific pattern
of the textile.
Dark fabrics absorb more of the available daylight
than paler ones. When the openness factors are equal,
a dark fabric will often have a lower value of Tv than
a paler shade. However, there can be considerable
performance differences between fabrics of the same
colour. When choosing the textile, it is also important to
look at the Tv value to obtain a better understanding of
how the product performs.
The reflection value (Rs) refers to the percentage of
the total solar radiation reflected by the outside of the
material. Reflection values are largely determined by
the colour or any coating there may be on the outside of
the fabric.
Dark colours absorb more of the available light energy
and therefore provide lower reflection values. Paler
fabrics reflect more of the solar energy and offer higher
solar reflection values.
157

A standard black textile usually offers an Rs value of
close to 10% or even less, whereas a white fabric might
have an Rs value of 50%. As a general rule, Rs values
of over 30% provide some protection from solar heat,
whereas an Rs value of 50% or more provides good
thermal protection. It should be noted that there are
ways of influencing the reflection value of a fabric of
any given colour. In such cases, a coating is applied on
the outward-facing side of the textile.
OPENNESS
FACTOR
(OF)
Various properties are related to each other. The
relationship can be simply expressed in the formula
that was stated earlier:
VISIBLE
TRANSMITTANCE
(TV)
GLARE Use low OF Use low Tv
DAYLIGHTING
Use high Tv
VIEWS Use high OF Use low Tv
SOLAR HEAT
SOLAR
REFLECTANCE
(RS)
Use high Rs
For east and west-facing façades, in particular when
they have clear glass that is directly exposed to the sun
at sunrise or sunset, people often select textiles with an
openness factor of 3% or less (1% is recommended). The
lower openness factor creates a finer filter mesh over
the window and effectively scatters even the disc of the
sun when it is visible.
Fabrics with openness factors of 4% or less (2% is
recommended) are commonly used on south-facing
windows and façades. Windows for light coming from
the north often have fabrics with larger openness
factors, allowing more of the directly available ambient
light into the space.
A textile with a low Tv value also provides good diffuse
daylight regulation and limits the chance that the fabric
will get too bright when dealing with intense daylight
circumstances. Do not forget that white fabrics, even
with low openness factors, can become very bright
sources of dazzle when illuminated by direct sunlight.
As (%) + Rs (%) + Ls (%) = 100%
Textiles with different openness factors are often
considered for projects so as to best meet the needs for
regulating direct sunlight, depending on the direction
the façade is facing and the height.
If the design aim is to maximise the amount of glarefree
daylight in a space to save the most energy, it is
better to select textiles with higher Tv values. A higher
Tv value increases the amount of light, both direct and
diffuse, that can pass through the cloth into the space.
The sharpness and clarity of the view through
a fabric can be predicted as a function of the
Tv value and openness factor. Dark fabrics with
higher openness factors generally give a higher
degree of clarity, followed by dark-coloured fabrics
with low openness factors. Pale-coloured fabrics
158

usually interfere most with the view outside and
give somewhat confused or muted versions of the
surrounding colours.
Until recently, there were no statistics that defined
the clarity of the view to help a design team specify
a textile in a specific project. The View Clarity
Index (VCI) ranks the clarity of the view from 0
to 100%. A value of 100% means that the fabric
causes no observable interference with the outside
view. At 50%, most objects on the other side are
recognisable, although the edges are blurry and the
colours are visible but washed out. A value of zero
means that you cannot see through the fabric.
Manufacturers have developed colours that
improve thermal management without negatively
influencing the view outside. Double-sided fabrics
were introduced to provide a considerably improved
Rs value, often above 50%, which drastically
improves the fabric’s heat repulsion without
sacrificing the clarity of the objects or colours on
the other side of the fabric.
In summary:
Pale colours
- Pale colours have higher Rs values, which means
that more heat is reflected. This can result in
lower costs for cooling in a warm environment.
- Paler colours also have higher Tv values,
meaning they cause more dazzle than darker
colours. This can be a problem in spaces where
the focus is on a computer screen.
- However, pale colours retain natural light
and can therefore lower the need for lamps
or overhead lighting.
Dark colours
- Lower Tv values allow for excellent control of
blinding. A darker colour would be a better option
for an entertainment space.
- A higher value of As means that more light
and heat are absorbed by the fabric, making
it less efficient for lowering cooling costs than
those with paler colours. In a very warm area
and for windows with a view of the sun during
the daytime, a dark colour might not be the
best option.
- Dark colours give a better view out during the
day, making the environment more visible.
- Dark colours show dirt less obviously than paler
colours, which can also be taken into account
based on the location.
159

160

APPENDICES
161

APPENDIX 1: COLOURS
Anything an individual perceives visually that is not related to their perception of shape, size, surface
texture, tone and movement of objects can be called ‘colour’.
Some substances are colourless – take oxygen, for
example. Various conditions have to be met if a colour is
to be observed or a sensation of colour perceived. Light
– a form of electromagnetic radiation – of a certain
wavelength must be emitted or reflected by an object.
The wavelength determines whether the colour is red,
green or blue. Or a combination of the three. Colours
can only be perceived when the human or animal has a
properly functioning physiological system.
Light has to be present for colours to be seen. Most
light sources produce light in a variety of different
wavelengths. Visible light consists of a broad range
of colours that can be seen when a prism is used. A
prism can refract light to break it up into its constituent
colours. This range of colours is referred to as the
spectrum and its colours, which each have their own
wavelengths, always appear in the same sequence
from red at one end through orange, yellow, green,
blue and indigo to violet at the other. Red light has the
longest wavelengths, green is in the middle and blue
has short wavelengths.
162

380
V B G Y O R
450
495
570
590
620
750
Color Wavelength Frequency Photon energy
violet 380 - 450 nm 668 - 789 THz 2.75 - 3.26 eV
blue 450 - 495 nm 606 - 668 THz 2.50 - 2.75 eV
green 495 - 570 nm 526 - 606 THz 2.17 - 2.50 eV
yellow 570 - 590 nm 508 - 526 THz 2.10 - 2.17 eV
orange 590 - 620 nm 484 - 508 THz 2.00 - 2.10 eV
red 620 - 750 nm 400 - 484 THz 1.65 - 2.00 eV
Source: quora.com
Cosmic
radiation
X-rays
Ultraviolet
radiation
Visible
spectrum
Infrared
Radar
Radio
1x to 100 pm
100 pm to 1 nm
1 nm to 380 nm
380 nm to 700 nm
700 nm to 1 mm
1 mm to 30 cm
30 cm to 100 m
380nm
Violet
380nm
Violet
380nm
Violet
380nm
Violet
380nm
Violet
380nm
Violet
380nm
Violet
Spectrum of visible colours
Source: marijkevanloon.nl
Source: Wikipedia
163

In reality, there are huge numbers of colours within the range of the spectrum because it is a
seamless scale and each of the colours gradually blends into the next. Each colour has its own
wavelength of light that stimulates the human eye to produce various colour sensations.
When we say that a clementine is orange-coloured, it would be more accurate to say that a sense of
orange is generated by an area of the retina (at the back of the eye) that corresponds to where light
rays from the clementine are received.
Anatomy of the eye
Retina
Ciliary body
Choroid
Cornea
Optic nerve
Iris
Lens
Optic disc (blind spot)
Sclera
Vitreous body
© Oogfonds
Source: oogfonds.nl
White light contains three primary colours: red, green and blue. These colours are referred to as
'primary' because they are colours in themselves and they cannot be replicated by mixing other
colours (of light). When the three colours are recombined, it produces white light again; this process
is called additive colour mixing and it underpins the way projectors and computer screens work.
They can be combined to produce the sensation of any other colour and are sometimes also called
‘spectral’ colours.
In pigments, dyes and inks, those primary colours almost always reappear. They can be mixed to
produce other colours and are known as subtractive primary colours because any colour that is
a combination is the result of subtracting (or absorbing) white light, either partially or completely.
These properties are utilised by painters and printers. If all three subtractive colours are applied,
black is created.
164

165

APPENDIX 2: GREENGARD GOLD (LEED) CERTIFICATE
The Low-Emitting Materials Third-Party Certification table lists acceptable
certifications and programmes for the LEED v4 EQ Credit Low-Emitting Materials.
LEED v4 EQ Credit Low-Emitting Materials Third Party Certifications and Labels September 8, 2021
The following table lists acceptable certifications and programs for EQ Credit Low Emitting Materials.
Note that the LEED v4 credit also requires reporting on TVOC levels. The programs deemed acceptable
may already include this information-if they do not, project teams must request this additional
information.
Certification or
Program
BIFMA level (if 7.6.1
and/or 7.6.2 were
achieved in e3- 2011
or later)
Benchmark VOC
Green Building
Product
FloorScore
Green Label Plus
Green Seal GS-11
(Edition 4.0)
Intertek Clean Air
Silver
Program
Documents and
Revision Dates
ANSI/BIFMA e3-2011
11/17/11
WI-012 Version 0,
Revision 8/30/2018
SCS-EC10.3-2014
September 2015
Process and
Procedures Manual
11/10/2015
GS-11 Standard for
Paints, Coatings,
Stains, and
Sealers, Edition 4.0
September 2021
A2LA accreditation
3/15/2016
Testing Standard
Referenced in Credit
ANSI/BIFMA M7.1-
2011
CDPH Standard
Method v1.1
ANSI/BIFMA M7.1-
2011 (R2016)
Composite Wood
Products Regulation
CDPH Standard
Method v1.1
CDPH Standard
Method v1.1
CDPH Standard
Method v1.2-2017
CARB
ANSI/BIFMA M7.1-
2011
General Emissions
Evaluation
Yes
Yes Hard surface
flooring and flooring
adhesives
Yes Carpet, adhesive
and cushion
Yes
Emissions and Content Requirements Eligibility
VOC Content for
Wet-Applied
Yes
Composite Wood
Evaluation
Yes (if certificate
includes NAF or
ULEF exemption)
Furniture Evaluation
Yes
Yes (ANSI/BIFMA
e3-7.6.2)
Yes (ANSI/BIFMA
e3-7.6.1)
Certification or
Program
Intertek Clean Air
Gold
MAS Certified Green
NSF/ ANSI 332
SCS Indoor
Advantage Gold—
Building Materials
SCS Indoor
Advantage —
Furniture
SCS Indoor
Advantage Gold—
Furniture
TPC list CARB
ULEF label or CARB
Exempt
UL Greenguard
Certified
Program
Documents and
Revision Dates
A2LA accreditation
3/15/2016
MAS CG Program
Summary Dec 2012
NSF 332-2015 Jan
2015
SCS-EC10.3-2014
September 2015
SCS-EC10.3-2014
September 2015
SCS-EC10.3-2014
September 2015
Per CARB website
UL 2818 3/14/2014
and UL 2821
3/14/2014
Testing Standard
Referenced in Credit
CDPH Standard
Method v1.1
ANSI/BIFMA M7.1-
2011
CDPH Standard
Method v1.1
CARB or SCAQMD
ANSI/BIFMA M7.1-
2011
CDPH Standard
Method v1.1
CDPH Standard
Method v1.1
CARB or SCAQMD
ANSI/BIFMA M7.1-
2011
ANSI/BIFMA M7.1-
2011
Composite Wood
Products Regulation
ANSI/BIFMA M7.1-
2011
General Emissions
Evaluation
Yes
Yes
Yes resilient flooring
Yes
Emissions and Content Requirements Eligibility
VOC Content for
Wet-Applied
Yes
Yes
Composite Wood
Evaluation
Yes
Furniture Evaluation
Yes (ANSI/BIFMA
e3-7.6.2)
Yes
Yes (ANSI/BIFMA e3
7.6.1)
Yes (ANSI/BIFMA e3
7.6.2)
Yes (ANSI/BIFMA e3
7.6.1)
166

Certification or Program
UL Greenguard Gold
Berkeley Analytical
ClearChem
Collaborative for High
Performance Schools
(CHPS)
Blue Angel Floor
Covering Adhesives
and other Installation
Materials
Blue Angel Elastic
floorings
Blue Angel Textile
floorings
Blue Angel Thermal
Insulation Material and
Suspended Ceilings
Program Documents
and Revision Dates
UL 2818 3/14/2014 and
UL 2821 3/14/2014
BkA-CC-01.2 8/31/2015
Procedures and
Standards for Product
Inclusion Version 2.0 +
July 2012 CHPS Criteria
Interpretation 7/1/2012
RAL UZ 113 May 2009
RAL UZ 120April 2010
RAL UZ 128 July 2011
RAL UZ 132 Oct 2010
Testing Standard
Referenced in Credit
CDPH Standard Method
v1.1
ANSI/BIFMA M7.1-2011
CDPH Standard Method
v1.1
CARB or SCAQMD
CDPH Standard Method
v1.1
AgBB
AgBB
AgBB
AgBB
General Emissions
Evaluation
Yes
Acceptable for first party claims
Yes
Yes products with
selfcertified claims
but excluding products
recognized only via CHPS
approved thirdparty
certifications
For projects outside the U.S.
Yes** (if additional
low formaldehyde
requirement is also met)
Yes** (if additional
low formaldehyde
requirement is also met)
Yes** (if additional
low formaldehyde
requirement is also met)
Yes** (if additional
low formaldehyde
requirement is also met)
Emissions and Content Requirements Eligibility
VOC Content for Wet-
Applied
Yes
Composite Wood
Evaluation
Furniture Evaluation
Yes (ANSI/BIFMA e3
7.6.2)
Certification or Program
Program Documents
and Revision Dates
Testing Standard
Referenced in Credit
General Emissions
Evaluation
Emissions and Content Requirements Eligibility
VOC Content for Wet-
Applied
Composite Wood
Evaluation
Furniture Evaluation
Blue Angel Flooring
underlays (cushion)
RAL UZ 156 Feb 2011
AgBB
Yes** (if additional
low formaldehyde
requirement is also met)
eco-INSTITUT-Label
Construction products
& floor coverings March
2015
AgBB
Yes** (if additional
low formaldehyde
requirement is also met)
NaturePLUS
GL0100, GL0400,
GL0600, GL0700,
GL0800, GL0900,
GL1000, GL1200,
GL1300, GL1400, GL1700,
GL1800 June 2015
AgBB
EMICODE EC1 07/28/2010 AgBB
EMICODE EC1 PLUS 7/28/2010
GUT GUT Test Criteria 2011
Indoor Air Comfort
Indoor Air Comfort GOLD
Blue Angel Composite
wood panels
Indoor Air Comfort
version 7 May 2021
Indoor Air Comfort
version 7 May 2021
AgBB+ low formaldehyde
requirement
AgBB + low
formaldehyde
requirement
EN 16516
AgBB + low
formaldehyde
requirement
Yes** (if additional
low formaldehyde
requirement is also met)
Yes** (if additional
low formaldehyde
requirement is also
met. EMICODE has
formaldehyde limit of 50
μg/m3 after 3 days)
Yes***
Yes textile floorings
Yes***
Yes***
Yes
Yes Yes Yes
RAL-UZ 76 Apr 2011 EN-717-1:2004 Yes
Byggvaru bedömningen (BVB) November 9, 2011 EN-717-1:2004
Yes, Recommended
criteria met in 8.3
Certification or Program
Program Documents
and Revision Dates
Testing Standard
Referenced in Credit
General Emissions
Evaluation
Emissions and Content Requirements Eligibility
VOC Content for Wet-
Applied
Composite Wood
Evaluation
Furniture Evaluation
French VOC emissions
labeling
March 25, 2012 ISO 16000 Yes, Class A or A+
Finnish Emission
Classification of Building
Materials
TÜVRheinland Green
Product Mark Furniture
Taiwan Healthy Building
Material Label
M1-The emission
classification of building
materials November
15, 2017
ISO 16000 + low
formaldehyde
requirement
Yes, M1
LVI 05-10440 en EN-717-1:2004 Yes, M1
M1- The emission
classification of building
materials November
15, 2017
ANSI/BIFMA M7.1-2011
Yes, M1 (ANSI/BIFMA e3
7.6.2)
2PfG E1992:12.2012 ANSI/BIFMA M7.1-2011 Yes (ANSI/BIFMA e3 7.6.1)
Operation Directions for
Taiwan Healthy Building
Material Label and
v1/02.11.2019
CDPH Standard Method
v1.2-2017
**The formaldehyde limit of 10 μg/m3 at 28 days must also be met when using the AgBB alternative, as specified for class A+ in French compulsory VOC emission class labeling.
***Additional information regarding the formaldehyde limit at 28 days is not required for products meeting EMICODE EC1plus. Additionally, products meeting EMICODE EC1 or EC1plus
automatically meet the wet-applied VOC content requirements, without additional documentation.
Yes
167

APPENDIX 3:
THE OEKO STANDARD
STANDARD 100 from OEKO-TEX® is a label
showing that the textile has been tested to
confirm that no harmful substances have been
used. The standard tells you that the item has
been tested for harmful substances and is
therefore harmless to human health. The tests
are carried out by our independent OEKO-TEX®
partner institutes on the basis of criteria laid
down in a catalogue.
The test takes account of numerous regulated and
unregulated substances that may be harmful to human
health. In many cases, the limit values for STANDARD
100 are stricter than national and international
requirements. The criteria catalogue is updated at least
annually and expanded with new scientific knowledge
or legal requirements.
In principle, any textile item at any stage of processing
is suitable for STANDARD 100 certification and may
therefore apply to semi-finished or finished articles,
such as baby textiles, clothing, domestic fabrics or
decorative materials.
Product class IV covers decorative materials and
includes all such items, including initial products and
accessories used for furniture and interior decoration
(e.g. tablecloths, curtains and upholstery fabrics).
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169

APPENDIX 4: PROPERTIES OF TECHNICAL FABRICS
Fabrics for indoor use, e.g. Kvadrat technical fabrics
812 816
KVADRAT TECHNICAL FABRICS
Originals
849 878 890
103
Comfort screen
203
Silver screen
Omniscreen
3%
Silverscreen
2% Low E
Silverscreen
4%
Openness factor (%) 5 23 2 0 0 3 3 3-4 2 4
Energy behaviour:
Absorption in % 29 27 30 29 30 31 13 20 15 17
Reflection in % 62 44 65 68 70 62 82 74 82 77
Transmission in % 9 29 5 3 0 7 5 6 3 6
Composition Trevira CS Trevira CS Trevira CS Trevira CS Laminated PVC 75% PVC 75% PVC 75%
Polyester PET 25% PET 25% PET 25%
Weight (g/m2) 95 70 132 142 325 250 450 440 400 400
Thickness (mm) 0,2 0,23 0,26 0,23 0,33 0,44 0,58 0,55 0,5 0,5
Certification:
OEKO TEX 100 IV V V V V V V V V
GreenGuard Gold (LEED) V V V V V V V
Flame retardant V V V V V V V V V V
Anti microbial V V V V V
PVC-free V V V V V
Helioscreen
Serge 3% Serge 1% Staccato Scale
Openness factor (%) 3 1 5 5
Energy behaviour:
Absorption in % 14 61 65 72
Reflection in % 67 32 28 21
Transmission in % 19 7 7 7
Composition PVC coated PVC coated PVC coated PVC coated
Glass fiber Glass fiber Glass fiber Glass fiber
Glass 41,5% Glass 41,5% Glass 41% Glass 41%
PVC 58,5% PVC 58,5% PVC 59% PVC 59%
Weight (g/m2) 544 474 457 601
Thickness (mm) 0,8 0,6 0,58 0,79
Certification:
OEKO TEX 100 IV V V
Flame retardant V V V V
BREEAM
Visual comfort is an important aspect of BREEAM,
a leading and very widely used environmental
assessment method for buildings in Europe. Various
credits can be earned (depending on the fabrics used)
for managing daylight penetration, glare control and
the outward visibility. Fabrics often also add to thermal
comfort and help create energy savings.
Solar control fabrics help to obtain credits in different
categories:
- Reducing the energy consumption of the building
[MAN 05]
- Visual comfort [HEA 01]
- Quality of the air indoors [HEA 02]
- Thermal comfort [HEA 03]
- Acoustic performance [HEA 05]
- Reduction of CO2 emissions [ENE 1]
- Innovation [INI]
The Dutch version of BREEAM even requires an
anti-dazzle class of 3.
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LEED
LEED is the North American equivalent of BREEAM.
It stands for Leadership in Energy and Environmental
Design. It aims to promote environmental awareness
among government authorities, architects, engineers,
developers and builders. The most recent version
of LEED is called LEED v4. Compared with LEED v3,
LEED v4 takes a more performance-based approach
to design, operations and maintenance that requires
measurable results throughout the project lifecycle.
Solar control fabrics help to obtain credits in different
categories:
- Ecological design of the premises
- Energy and ambience
- Materials and resources
- Quality of the indoor environment (low emissions,
natural ventilation, thermal comfort, natural
lighting and acoustic comfort)
- Innovation
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172

9PARAMETRIC DESIGN
173

PARAMETRISM
Parametrism is a style of architecture and product design that emerged around the end of the
twentieth century and beginning of the twenty-first. The architect Zaha Hadid is seen as its
founder. The design process uses parametric equations a great deal and relies heavily on the use
of software, algorithms and computers. From about 2020 onwards, not only parts of the outer
envelopes of buildings will be designed that way but also floor plans and lines of sight.
Parametrist buildings feature design patterns that are
often three-dimensional. The patterns in Parametrism
are neither completely loose nor fixed in a grid, but have
a certain coherence that is generated by calculations
(the parametric equations). These patterns tend to
change over a certain spatial distance.
In parametric building design, a decision is often
made not to include the functions in the design,
as was the case in Rationalism and Futurism. The
designs often have a clear principal form in which the
functional areas tend to flow into each other without
being clearly separated.
Zaha Hadid
Zaha was born on 31 October 1950 in Baghdad, Iraq.
She first studied mathematics at the American
University in Beirut (Lebanon) and then architecture at
the Architectural Association in London, where she also
first met the architect Rem Koolhaas.
After graduating in 1977, she worked at Koolhaas’ Office
for Metropolitan Architecture (OMA). She started her
own agency in 1979. Her designs from that time are
in the Deconstructivist style, with angular geometric
planes inspired by the Suprematism of Malevich and
El Lissitzky. Her work slowly became less Brutalist and
confrontational, with her later designs taking on
a much more sensual line pattern; the buildings were
also curved. She subsequently achieved the best score
in several international competitions. These designs
all remained unbuilt, though. Her first major design
to be built in Europe was the fire station on the Vitra
factory site in Weil am Rhein in 1993. This was followed
by a long line of designs that brought her international
renown and let her create impressive buildings all over
the world.
1992: Vitra Fire Station (1989-93) in Weil am
Rhein, Germany
1993: IBA Housing (1989-93) in Berlin, Germany
1999: Millennium Dome in Greenwich, UK
2002: Ski-jumping ramp in Innsbruck, Austria
2003: Contemporary Arts Center in Cincinnati, USA
2005: Central building of the BMW factory in
Leipzig, Germany
2008: Pabellón Puente (bridge) for the World Expo,
Zaragoza, Spain
2012: Aquatics Centre for the 2012 Summer Olympics
in London, UK
As an industrial designer, she also designed lounge
seating, ergonomic cooking islands, fittings for the
construction sector, a concept car and women’s shoes.
For the American art dealer Kenny Schachter, she
devised an eight-metre-long aerodynamic speedboat
174

Zaha Hadid’s final project:
the One Thousand Museum in Miami, USA
175

using asymmetric forms. Hadid’s agency also came up
with the set decor for a Pet Shop Boys tour.
By the end of her life, her own firm (Zaha Hadid
Architects in London) had grown into an organisation
with almost 400 staff and had completed over 950
projects in 44 countries.
The architect died on 31 March 2016 of a cardiac arrest.
She was in a Miami hospital at the time, being treated
for bronchitis.
In addition to designing complex geometry and
structures, parametric design also offers scope for
making changes at a later stage in the design process,
using a responsive model. The modifications and
scenarios can be tested and consequences made clear.
Because parameters can also be added during design
(geometric constraints, structural requirements or
material properties), better understandings of the
consequences for realisation – or production in the case
of an industrial manufacturing process – also emerge.
Parametrically designed
In parametric design, a design is generated on the
basis of data and the relationships between parts.
Defining those relationships is an essential component.
It is a digital process in which the consequences of
modifications or alternatives are calculated in a model.
Those understandings are incorporated in a data model
that works as a dynamic system.
The human brain is only capable of handling a couple
of variables at a time. Parametric design makes it
possible to weigh many alternatives up against each
other; in fact, you produce the design by calculating
variations with specialised software, thereby making
the consequences evident. On top of that, you can
deploy artificial intelligence to let you proactively ask
the system to make suggestions.
In parametric design (also known as informed design or
associative design), utilising algorithms allows designs
to be generated rather than being created: it therefore
also gets called ‘generative’ design.
A parametric process reduces the risk of errors and
makes it possible to clarify the various designs, for
instance through simulations. It yields greater design
freedom without directly compromising efficiency.
The process requires relationships (processing logic)
between the parameters. The designer defines not
only the parameters but also the processing logic
(the modelling) and so the software works as per
the designer’s definitions, with the designer always
being able to tweak the model. Such models are often
created by architects in cooperation with programmers.
Modelling is complex, but you don’t have to start from
square one every time, as the models can in fact be
used very nicely in subsequent projects.
Parametric design therefore does result in a shift in the
tasks: from repetitive work to investing in good models
from a cross-project perspective, and with more time
during the projects for integral coordination and the
creation of genuine added value (plan improvement,
cost reductions, etc.).
176

The role of the architect in parametric design work
Using algorithms created by the architect in
cooperation with programmers allows designs to
be generated (generative design). This changes the
architect’s role: after all, the optimum solution must be
selected from all the possible alternatives. Architects
are thus better able to spend their time efficiently on
other aspects of the building.
Visual programming
Nowadays, the visual approach to parametric design is
being used more and more widely because it is more
accessible and there is less of a barrier to using it.
Visual programming makes it possible to set up a logic
model without a need for textual coding.
The case of textual programming is also referred to
as a ‘code approach’, whereas scripting is a ‘low-code
approach’ (as scripting offers a textual programming
method for combining pre-programmed building blocks)
and the case of parametric modelling is known as a ‘nocode
approach’ because the programming is done visually.
Parametric modelling offers important new possibilities
for recording logic and reasoning in the computer
and ‘playing it back’ in an automated way. When a
parameter (an input) is changed, the logic model is
recalculated using the relationships defined.
Spreadsheets are not parametric software, strictly
speaking, but they behave similarly: parameters can
be defined (as numbers in cells) and relationships
set up (by adding formulas). When an input is
modified, changes are automatically processed in the
spreadsheet by the logic defined.
Parametric software use is rising strongly as an
addition to BIM, and also increasingly offers links to
other simulation and analysis software, which can
often be used as plug-ins. Plug-ins are needed if you
are to make the best possible use of Grasshopper.
The Kangaroo plug-in, for instance, helps optimise
the construction of your design (form-finding) and the
Ivy plug-in helps create two-dimensional surfaces
corresponding to a 3D design, as is often needed when
producing a design.
Parametric design can also be easily used for
convincing stakeholders of what they want so that they
make better choices. You can show them live what the
consequences of specific choices are. Knowing that
most incident light comes from the south and east can
be a good reason to orientate certain rooms to suit.
Grasshopper helps understand how long the sun shines
in for during the day and how much incident daylight
there actually is.
Examples of widely-used visual software packages are
Grasshopper, Dynamo and Generative Components.
Nowadays, it is also possible to use parametric models
in online or shared environments so that the only thing
needed for accessing the model is a web browser.
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178

Selecting the principles
Parametric designs can for example focus on the health and
well-being of a building’s users. It is not primarily about a
special building design per se; using a parametric model as
an optimisation process can however also make a building
measurably healthier and more sustainable.
To create a parametric model, data and relationships between
elements of a structure are analysed using algorithms.
The algorithms can be used to get the optimum amount
of daylight into the premises, for example. For BREEAM
and WELL, you might want to maximise the parameter for
incoming light while at the same time minimising the one for
the warming it causes, so that you do not need a large airconditioning
system. Many architects then have a tendency to
design glass buildings, but that is no longer a contemporary
solution at all. 9001
The link between health, well-being and the façade
The link between health, well-being and the façade is an
obvious one to make, via the light and ventilation. As the
façade is part of the building shell or envelope – a key aspect
that an architect explicitly focuses on – it is an important
transition. When you look at the building envelope, the façade
does after all usually constitute an important aspect of the
design signature.
Parametric design means you develop more continuously,
instead of a trial-and-error approach until a design optimum
is achieved. That optimum is normally defined in advance.
Changes to a design are almost inevitable but they can be made
much more efficiently when based on a parametric design.
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If a façade is programmed using various elements
and requirements in a dataset, you can always get it
regenerated after changes to the design. That also
saves time and money. Parametric design may be timeconsuming
during the early phases but that digitisation
process delivers nothing but benefits later on. 9001
The main driving forces for parametric design:
Design
For complex shapes, such as spherical structures or
other double-curved surfaces, a parametric model can
help generate a 3D model quickly.
Why use associative design?
Parametric design can also be referred to as
‘parametric and associative design’. Associative means
that there are relationships (processing logic) between
the parameters. In parametric design, the designer
defines not only the parameters but also the explicit
processing logic (the modelling).
In real-world terms, this means that parametric design
will do exactly what the designer wants to achieve.
The software is not a black box with hidden internal
workings; the designer defines the rules, assigns the
values, can see precisely what is happening, and
initiates the adaptations.
The parametric model reinforces the creative
process by showing how much is possible, given
the preconditions that have been imposed, and that
is often much more than the designer might have
imagined beforehand. Values can be added and
modified throughout the process. This lets the model
become more and more refined until the desired result
is achieved.
Production
When there is a lot of repetition of the same type
of calculations, parametric models can speed up
the production process, for instance by generating
quantities, reports and design drawings.
Optimisation
Structures that a fully parametric model has been
created for are often suitable for optimisation
studies. Evolutionary algorithms are used to perform
optimisations more efficiently. Galapagos by
Grasshopper is an example of one such algorithm.
Flexibility
Flexibility is valuable during the design process. A great
deal is still unclear at the start of a design process.
A parametric model lets the designer make changes
quickly and map out the consequences. If there are
changes, the same actions do not have to be repeated.
There may be some market reluctance to adopting
new technology. Parametric designing also requires a
different working method. It can engender a shift from
repetitive work to more time for integral coordination.
It could also potentially lead to alternative business
and earnings models.
180

Does the market pay for the delivery of a design, for
each variant, for the insights into the design choices or
for the added value of advice? There will very probably
be a shift towards higher-quality advice with the quality
of the solution, the assistance provided or savings
on the design counting, instead of remuneration for
providing the initial solution.
We may cautiously conclude the following about
parametric design:
- The process is accurate, as it precisely follows
predefined rules.
- The quality is more consistent, with fewer
human errors.
- The models can be reused in subsequent projects.
- Simulation makes it possible to explore and
understand different design solutions.
- Relative performance can be quantified and
compared to alternatives.
- Solutions can be optimised.
- It adds flexibility to the design process;
potential changes can be anticipated.
- Design freedom is retained.
- The process is made more efficient: less effort
and shorter throughput times.
Notes
9001 Lennaert van Capelleveen, founder of ArchiTech Company
Sources consulted:
- Interview with Maria Selkou (1985), architect at ZJA Zwarts & Jansma Architecten
for the BNA Academy
- Kennisportaal Constructieve Veiligheid; Best practices voor parametrisch ontwerpen,
Digital Developments Task Group, version of 16 February 2021
- Architectuur NL: BNA Academie/Workshop on parametric design provided by
Pim van Wylick and Gijs Joosen.
- Blog on Architectenweb, interview with Lennaert van Capelleveen,
founder of ArchiTech Company
- Wikipedia
- The Guardian, 8 September 2013, Rowan More, “Zaha Hadid, Queen of the curve”
181

182

10
MODEL FOR ENERGY CONSUMPTION AND
CO2 EMISSIONS IN AN OFFICE SPACE
183

INTRODUCTION
In this chapter, we examine the options for gaining an understanding of the energy consumption in
an office space.
This question arose from the need to investigate the relationship between energy consumption in
a room used as an office and the use of dynamic solar shading. It is the second major step in our
quest to answer four questions:
- What influence does applying dynamic shading
have on productivity, primarily of people in office
environments?
- What is the relationship between the use of
dynamic shading in an office environment
and energy consumption, with its associated
CO2 emissions?
- Can we bundle all these influences together into
a single model so that we can provide wellfounded
answers to questions that matter when
making investments in dynamic shading, about
payback times and returns on investment?
- Can a parallel be drawn for the same questions
for non-residential buildings in other sectors,
such as education and healthcare?
adjusted. The results are being published in the second
revised reprint of The Somfy Factor, Part 1.
For putting flesh on the bones of the questions about
energy consumption and CO2 emissions in office
buildings, a two-step approach was chosen, first trying
to determine the relationship between the use of
dynamic shading and energy consumption (as well as
CO2 emissions) for one office room, followed by
a model mapping out the same relationship for an
entire building.
Once the relationship has been defined for an office
building, a similar setup can be used at a later stage for
buildings in the education and healthcare sectors.
The issues are therefore about buildings with very
different uses on the one hand, and on the other also
about very different fields of science – which is why the
decision was made to separate out the issues first and
only then to try to recombine them again afterwards.
The relationship between the use of dynamic shading
and productivity in office environments has already
been examined, described and modelled (see also The
Somfy Factor, Part 1), looking at office buildings. A
further study for the education and healthcare sectors
was based on that, with the productivity perspective
For the purposes of this book, we first tried to produce
a model describing the relationship between dynamic
shading and energy consumption (plus the associated
CO2 emissions). That gave an opportunity to combine
the issues linked to productivity, energy consumption
and CO2 emissions into an integrated parametric model.
To implement that model, a project was set up that was
split into three phases, the first of which is the subject
of this chapter of the book:
184

Phase 1: A model of dynamic shading versus energy
consumption in a room used as an office.
Phase 2: Extending the Phase 1 model with available
data – research into productivity in an office
environment.
Phase 3: A complete model in which all aspects are
clearly and integrally visualised, with a plug-in
so that the model could also be applied in
other countries.
Energy management in an office
Parametric design lends itself well to a study in which
the requisite variables are linked to a typical room
(a standardised office of 3.6 x 5.4 x 2.7 m). We can
then work out various aspects on that basis, such as
daylight, the view out, energy, indoor climate, cold air
downdraughts and noise.
As a starting point for constructing the model, we take
the variable s that we used for modelling productivity
(see The Somfy Factor, Part 1) and provide outcomes
that are applicable to the Dutch climate.
Two software tools are used to construct the model
and make the results visible, Ladybug Tools and
EnergyPlus. Although the climatological data focuses
on the Netherlands initially, it can subsequently be
converted relatively easily to other geographical areas,
so that similar models can be constructed for locations
elsewhere in the world.
Step-by-step working method:
185

Scripting
To do the calculations, a script has to be developed (with the help of software).
Overview of the modelling
A visualisation is given below of the model, in which the relationships between the various elements
have been worked out based on the predefined variables.
Model structure: made up of the following elements
1. Structural geometry
2. Dynamic solar shading
186

3. Defining the principles for the building systems
Calculating all the possibilities, assisted by the software
The next step is to perform the calculations using the software to run through all the possibilities.
To give you an idea: there are over 550 different conceivable scenarios that are then ranked
according to their outcomes.
All variables for the façade (see image below, in the horizontal direction) are calibrated to the
possible outcomes (see image below, in the vertical direction) by the model.
The software then calculates all possible combinations. The possible combinations and their
outcomes are shown along the vertical axes in the right-hand section of the figure below. The
results we are searching for are in blue above the axes (cooling load in summer, heating load in
winter and reduction in annual CO2 emissions to the far right).
187

188

189

Recording and selection
For all scenarios, the variables and their outcomes are defined using a fixed method so that
comparisons are possible. The least likely outcomes (or scenarios that overlap and may be less
likely or less relevant) can easily be eliminated to make the number of relevant scenarios and
possible outcomes more manageable.
All data remains available in an underlying database and can be called up for inspection
at any time.
Selecting relevant results
The relevant results can then be selected individually and displayed on a dashboard.
190

The calculations can thus be used to rank the results of
the various options.
Comparing the outcomes of various scenarios then
allows the influence of dynamic shading on the energy
consumption and CO2 emissions of an office to be
determined. The orientation of the façade, the glassto-wall
ratio and the type of glass used in the façade
can be freely adjusted, as can the use or otherwise
of dynamic shading. The model provides four variants
for the sun shading used: none, on the inside, on
the outside or a combination of indoor and outdoor
dynamic shading.
The results show the difference (i.e. savings) between
using dynamic shading or not for four possible
orientations of the façade: north, east, west and south.
The calculation took the following variables
into account:
- Glass percentage (30%, 50% and 70%).
- Orientation of the room.
- Type of shading.
- The location of the daylight control point.
- The control of automatic shading.
Step 2: Extending the model
Having constructed the model to identify the influence
of dynamic shading on energy consumption and CO2
emissions, we attempted to extend the model to include
the elements that determine the effect of dynamic
shading on productivity.
Several items had to be added to the model, as was
seen in Part 1 of The Somfy Factor.
Summary of Step 1
Principles used in the calculation:
- Standard-format office with a single outer wall.
- Dimensions 3.6 m by 5.4 m, 2.7 m high.
- Climatological data for Amsterdam.
- Reflection factors: wall 0.5, ceiling 0.7, floor 0.2.
- Rc value for the façade = 4.755 m2K/W.
- Thickness of the wall: 0.3 m.
- Occupancy: 1 person per 10m2 (2 people).
- Climate system design: ceiling induction units.
- CO2 figure converted from the NTA 8800 energy mix.
Parametric design also allows information from Excel
to be utilised. This lets us convert results from the other
model into a matrix. Converting the formulas used in
the original model means we can also directly link the
various productivity aspects to a space that we defined
earlier. This gives rise to a composite model that maps
the influence of dynamic shading onto the essential
parameters for productivity in an office environment.
These include air temperature, radiation temperature,
glare, the view to the outside and control of the
indoor environment.
191

Summary of Step 2
This addition creates an integral model in which we can link the results directly to each other.
A single model is created that brings together productivity, energy aspects and CO2 emissions.
The results can be bundled into a ready-to-use tool where everything can be presented visually
for all the relevant stakeholders, who can then make informed decisions based on costs, savings
and environmental aspects: information that is always substantiated and can also be reproduced
at any time.
Step 3: An integrated, international approach
In Step 3, we eliminated the assumptions that had been made as simplifications for modelling the
effect of using dynamic shading and replaced them with the variables from the parametric model
for calculating the effect of dynamic shading on energy consumption and CO2 emissions. This lets
us maximise the benefits of parametric modelling. Several variables in the two models are similar
and have now been allowed to vary when calculating productivity as well, making the results not
only accurate but also completely consistent. To that end, we also categorise productivity into
various classes, using the Programme of Requirements for Healthy Offices as a reference.
A major benefit of this approach is that the model can also be extended to other countries by linking
it to an alternative climatological file.
192

This method creates a huge database of results that can be accessed through Design Explorer
in a kind of dashboard. Modifying the variables allows suitable situations to be filtered and
displayed visually.
As an example, a figure is given here that shows daylight calculations.
To make the results available to the market and to allow discussion of the options with decisionmakers,
a web-based tool was developed with which simulations can easily be made for specific
situations, based on up to twenty reasonably easy-to-answer questions.
As a subsequent step in the context of this book, a model has been created that extrapolates the
situation in a single office room to a whole office building; that is covered in greater depth in the
following chapter.
Away from this book, work is now being done on two other steps:
- A model using climatological plug-ins that can be applied internationally.
- Tools that allow real-time monitoring of the situation in rooms or a building, thereby letting
users take corrective measures or apply automation (façade management systems).
193

194

11
PRODUCTIVITY AND ENERGY EFFECTS OF DYNAMIC SOLAR
AND LIGHT SHADING IN OFFICE BUILDINGS
195

INTRODUCTION
This chapter describes how the model for energy effects of dynamic solar and light shading for
office areas can be used to build a complete model for determining the energy effects in office
buildings. The model was completed by adding the productivity effects 1101 and the database needed
to make calculations for Dutch office buildings. The model was then used as the basis for
a practical web application for day-to-day use.
Adding climate plugins and various other data for financial
calculations to the underlying database allows the model
to be used at other geographical locations as well.
To get a usable end result, previous models were
tweaked and improved, paying attention too to potential
upscaling for other countries. The two models were then
integrated, also permitting several indoor environment
parameters to be calculated.
After random verification of the results, the
database was populated with all the data needed
for calculations for the Netherlands.
How the model and the web application fit together
User input
Standard office
• Climate
• Use
• Building characteristics
• Installations
Variable building characteristics
• % of glass in the façade,
• Presence of solar control glazing,
• Distribution of working areas over the façade,
• Number of working areas perpendicular
to the façade,
• Number of people working together
in a single room
• Presence of a cooling system,
• Employee occupancy of the working area.
Intervention to apply
• Daylight shading for each façade,
• Solar shading for each façade,
• Dynamic control
Parametric
model
Parametric
model
Post-processing
Web application
Post-processing
Web application
Reference model
• Productivity effect
• Energy performance
• Indoor environment parameters
Intervention variant 1
• Productivity effect
• Energy performance
• Indoor environment parameters
Output
Web
app
Gain of intervention variant 1
• Productivity potential
• Energy potential
• Indoor environment effect
• Pay-back period
• Return on investment
196

A summary of how it works:
1. Input: the web application user enters the
building characteristics and specifies the desired
interventions (solar and light shading systems).
2. Parametric model: performance figures for
energy, productivity and indoor environment
are mapped for the different variants given the
various input data items (i.e. depending on the
user’s input). All the necessary calculations
are carried out and the results are saved in a
database that is included in the tool.
3. Post-processing web application: the results
as included in the database based on the
parametric model need post-processing to
generate usable results for the user. Those
calculations are done in the web application.
4. Output: results that are relevant for the user
are presented in the application. You can see
what the effect of using dynamic solar and light
shading is on the productivity potential, the
energy performance, the indoor environment and
the financial calculations.
The ‘Somfy productivity and energy model for offices’
was developed to give a clear picture of the effects of
using dynamic sun and light shading in office buildings.
The model has a scientific basis and uses the most
advanced computer models, which have run hundreds
of simulations.
To gain an idea of how much the building
characteristics affect the productivity potential,
a best educated guess (estimate) is made of
the effect of solar and light shading systems
on the indoor environment, depending on various
building characteristics.
Generally, even if the model’s building and system
characteristics are the same as those of the
actual building, the results still depend heavily
on user behaviour.
The broad features of the building characteristics
can be entered into the model, although in practice
any building will deviate to some extent from the
assumptions made in that model. The results are in
particular meant to give a clear picture of the relative
effects of different interventions and the role of the
building characteristics.
Design and basic principles of the
parametric model
To estimate the influence of dynamic shades and
blind systems, a calculation model was first developed
for a ‘standard office space’. A number of variable
building characteristics were then added so that the
‘standard office space’ can be used as the baseline
for the calculations for an office building. That is how
the baseline ‘reference situation’ is created. The model
gives the option of adding various types of dynamic sun
and light shading systems for each façade orientation.
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Building characteristics of the ‘standard
office space’
Performance figures for the energy, productivity
and indoor environment were calculated for the
interventions to be used using a parametric model
in a visual environment (Rhino 3D) combined with
Grasshopper software and the Ladybug Tools plugin.
The model assumes a standard office space for which
fixed assumptions have been made regarding:
- Dimensions of the room.
- The climate.
- The times when the room is in use.
- Internal heat burden from people, devices
and lighting.
- Construction and insulation of the building.
- Heating, ventilation and window/purge ventilation.
See the assumptions made in Appendix 2 to this chapter.
The values that the different parameters can take are
described in Appendix 2.
Additionally, there are several building characteristics
for an office space (and how it is used) that can
additionally be included to give an estimate of the
productivity effect. Rather than including these
aspects in the parametric model, they are part of the
post-processing in the web application. The following
parameters are processed:
- Number of working areas perpendicular to the
façade (2 options)
- Number of people working together in a single
room (4 options)
- Employee occupancy of the working area
(percentage of the time)
- Distribution of the working areas over the various
façade orientations (percentage).
Variable building characteristics
Different variants of a standard office space were
used for the calculations, with the following building
characteristics varying:
- Façade orientation (4 options: north, east, south, west)
- Percentage of glass in the façade (3 options:
high: > 60%, average: 30-60%, low: < 30%)
- Presence of solar control glazing for each façade
(2 options: solar control glazing present or not)
- Presence of a cooling system (3 options: no
cooling system, top cooling, complete cooling).
Accumulating the possible combinations meant that
calculations were done for a total of 4x3x2x3 = 72
reference models.
The first part of the questionnaire in Appendix 1
(I. Building characteristics) shows the questions that
the user can use to specify the desired input values for
these variables.
Characteristics of interventions for solar and
daylight shading
The tool has various options for applying dynamic sun and
light shading devices. The following definitions are used:
- Light shading: products that are generally applied
on the inside of a building (blinds, plissé, etc.)
- Indoor solar shades: the same products as
light shading but with a reflective aluminium
microlayer, also used on the inside.
- Solar shading: screens on the outside of a building.
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The user can choose to use the following (alone or in
combinations) for each façade:
- daylight shading (yes/no)
- solar shading (choose one of four types/none)
Additionally, there are various possible types of
operation: automatic (switch criterion 150 W/m2) or
manual (switch criterion 300 W/m2). The specifications
of these systems used, such as the LTA (light
transmission factor) and the g-values (solar factor), can
be found in Appendix 3, as well as the guiding principles
for the various types of system control mechanisms.
The questionnaire about which intervention to use is
given in Appendix 1 (III. Intervention to apply).
Energy performance figures
A full year was simulated for each scenario for the
model and the interventions. This includes a look at
the energy required for heating and cooling the space
in question per hour. The calculation takes account
of both internal and external factors that influence
the cooling and heating requirements. These average
hourly values were then translated to the outcome
measures described below, so that different scenarios
can be compared. The following results were generated
by the calculation model:
- Energy requirement for cooling per season per
year in kWh/m2.
- Energy requirement for heating per season per
year in kWh/m2.
- Total energy requirement for heating and cooling
per year in kWh/m2.
The amount of heating and cooling energy per m2 floor
surface area was chosen for this because it can easily
be translated to an entire building with façades facing
in different directions. Moreover, this unit can be easily
used to compare two different buildings that differ in size.
Post-processing in the web application
If choosing to use both sun shading and light shading,
the principle is that light shading is used in the autumn
and winter to prevent dazzling and solar shading is used
in the spring and summer to prevent both dazzling and
undesired heating in a room. The parametric model
does not yet take account of the efficiency of the
source of heating or cooling. The energy requirement for
this is still corrected with a coefficient of performance
(COP value) as given by the user (Question 6, Appendix
1) to obtain a picture of the associated energy
consumption. To estimate the costs needed for cooling
and heating in various scenarios, the calculated energy
consumption (kWh/m2) is multiplied by the number of
square metres of office space. The estimate for the
number of square metres of office space is made by
multiplying the number of FTE of office employees (see
questions 9 or 9a and 9b, Appendix 1) by the available
floor surface area per employee (FTE) per room
(Question 12b, Appendix 1).
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In addition to energy consumption, the associated
CO2 emissions and costs were also considered. The
following principles are used for this:
- CO2 emissions: 0.34 kg/kWh (based on NTA 8800).
- Energy costs are given in euros, assuming an
energy price of €0.25 per kWh (all-electric system).
These costs are used to calculate the payback times
and the return on investment (ROI) due to the difference
in energy costs. The expected investment for daylight
and solar shading systems is divided by the annual
difference in energy costs (variant minus reference).
Productivity potential for each indoor
environment parameter
We are going to look more closely now at the principles
used to make calculations of the potential productivity
effect for each parameter.
Air temperature
A literature study 1101 shows that the productivity potential
decreases with an increasing temperature (from about
23°C upwards). The theoretical productivity effect as a
result of the air temperature is determined for various
temperature ranges, as shown in the following table.
Overview of assumptions of the effect of air temperature
on productivity (columns 1 and 2) and examples of
possible outcomes of a variant (column 3).
Temperature range
The air temperature in the room was modelled using
the specified building characteristics. Models were
made for all possible combinations of the reference
models and interventions to see what percentage of
time (during the period of use) a particular temperature
interval applied for (see calculation in the table,
right-hand column). The productivity effect per year
per variant was then calculated by multiplying the
applicable time percentages by the productivity effect
factor for that temperature interval (the final row in the
table). The productivity effect due to the air temperature
per façade is a direct outcome of the parametric model.
Radiant heat
Assumed
productivity effect
In addition to the influence of the air temperature, the
effect of radiant heat due to incoming solar radiation
falling directly on people who may be in the office
building was also looked at. The influence of this on
productivity is determined based on the influence of
solar radiation on the sensation of heat according to the
PMV model (at a constant air temperature).
period of use
Reference model v1
< 24°C 0% 59%
24 < 26°C -0.8% 22%
26 < 28°C -3.2% 19%
28 < 30°C -6.4% 0%
30 < 32°C -10.5% 0%
> 32°C -13.9% 0%
Productivity effect -0.78%
Based on a literature study 1101 , the basic principle is that
a one-point rise in the PMV (compared to neutral) gives
an estimated productivity effect of -2%.
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To map out the influence of the solar radiation alone, the PMV value is calculated twice:
1. Radiant heat falling directly on a person and affecting the air temperature.
2. Air temperature rise due to incoming solar radiation without the radiation component
The difference between the two calculations is the increase in PMV value that can be
attributed to the radiation component of the incoming solar radiation.
Radiation component of direct solar radiation ingress
The effect of radiant heat is calculated as the difference in radiation temperature as
a function of incoming solar radiation and air temperature (ΔMRT). The solar radiation
ingress can be calculated based on the parameters in the table below.
Parameters needed to calculate radiation temperature due to incoming solar radiation
with the value or range used in the productivity tool (ASHRAE-552) 1102
Radiant heat parameters
Value/range
used
Dependent on building
characteristics
Source
1) Absorption of short-wavelength IR 0.7 Constant Default ASHRAE-55
2) Angular elevation of the sun 38° Constant latitude 52°N (21 Mar and 21 Sep)
3) Angle of façade w.r.t. person 90° Constant
4) Proportion of the sky visible to the user 0.1-0.3
Distance to the façade’s
glass surface
ASHRAE-55 (perpendicular to
the façade)
ASHRAE-55
5) Proportion of the body exposed to sunlight 0.3-0.7 Glass surface ASHRAE-55
6) Incident solar radiation
Parametric
model
Façade orientation
Climatological file
7) Ingress of sunlight g-value Glazing, intervention Appendices 2 and 3.
The first three parameters are assumed to be constant in this scenario. Parameters 4
and 5 depend on the building characteristics (distance of working area to the façade
and the glass surface): the influence of radiant heat on the sensation of warmth
decreases the further from the window you are (distance between working area and
façade). Additionally, the influence is smaller when the glass surface is smaller
because there will be less ingress of solar radiation. The values to use are based on
ASHRAE-55 (see Appendix 4). ΔMRT can be calculated in an online PMV calculator 1103
using the seven parameters in the previous table. A building factor was calculated for
each combination of building characteristics (six possibilities), where:
ΔMRT (°C) = building factor (°C/(W/m2)) * solar radiation * 10-2 (W/m2) * g-value
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A recap of the building factors as calculated is given in the overview below.
Building factor based on the building characteristics for calculating ΔMRT in °C/(W/m2).
2 desks or fewer 3 desks or more
Not much glass 60% 3.4 3
A simplification was made with the aim of limiting the possible outcomes in the
parametric model and keeping the time needed for the calculations at a sensible level.
For that reason, ΔMRT without the building factor was used: ΔMRT model = ΔMRT ÷
building factor.
However, the influence of the building factor was added in during the post-processing.
Calculating the sensation of heat (PMV model)
Input parameters for the PMV model for each season
Winter Spring Summer Autumn
With
radiation
No
radiation
With
radiation
No
radiation
With
radiation
No
radiation
With
radiation
No
radiation
Air temperature (°C) Ta Tawinter Tawinter Taspring Taspring Tasummer Tasummer Taautumn Taautumn
Radiation temperature (°C) MRT MRTwinter Tawinter MRTspring Taspring MRTsummer Tasummer MRTautumn Taautumn
Air humidity (%) RH 50
Air speed (m/s) V 0.1
Activity (MET) A 1.1
Clothing insulation (clo) I 1 0.8 0.6 0.8
PMV (-) PMVwinter PMVnr-wnt PMVspring PMVnr-spr PMVsummer PMVnr-smr PMVautumn PMVnr-autm
ΔPMV (=PMV-PMVnr) ΔPMVwinter ΔPMVspring ΔPMVsummer ΔPMVautumn
The air temperature (Ta) and the radiant heat (MRT model) are calculated in the parametric
model. The ‘clothing insulation’ parameter was made into a variable depending
on the season. The assumptions for air humidity, air speed and activity are fixed values.
The calculation of the PMV value was done in accordance with NEN-EN-ISO 7730.
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The value for each façade can then be calculated by working out the annual average
for the four seasons. The yearly average ΔPMV value due to radiant heat is multiplied by
-2.0% in the parametric model to give an estimate of the productivity effect per façade.
The outcome of the parametric model is the provisional productivity effect of radiation
per façade.
Pradiation yearly avg.= -2% * (ΔPMVwinter + ΔPMVspring + ΔPMVsummer + ΔPMVautumn) ÷ 4
The influence of the building (building characteristics) is included in post-processing
by taking account of the distance to the façade and the glass surface. The provisional
productivity effect due to radiation as known in the parametric model is therefore
multiplied in the web application by a factor that depends on the distance to the façade
and the glass percentage in the façade.
Productivity effect per façade: Pradiation = Pradiation yearly avg. * building factor
Glare
Due to the limited number of studies into the influence of dazzling or glare on
productivity, the average of the outcomes of dazzling and visual comfort was taken:
-11% and -3% respectively. 1101
Because the scientific underpinnings for the effects of glare are poor and the value for
glare is very high, the potential effect in the model has been reduced by 50%: if there is
a risk of glare, the calculation uses a productivity reduction of 3.5%.
In practice, the risk of glare due to daylight (daylight glare probability or DGP) depends
on the position and the line of sight. To get an idea of the probability of glare for a whole
room, the UDI (useful daylight illuminance) is used.
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The UDI uses the following categories:
< 100 lux = too little daylight
100 – 300 lux = additional lighting needed
300 – 3000 lux = enough daylight,
no additional lighting needed
> 3000 lux = too much daylight,
risk of nuisance/glare
The light intensity in an office space due to daylight was
modelled based on the specified building characteristics.
For all possible combinations of reference models and
interventions, the percentage of time (during the period
of use) when the UDI value is higher than 3000 lux (for at
least 50% of the floor surface) was calculated, because
in these cases there is a risk of glare due to daylight.
After that, post-processing is done in the web application.
After all, the further people in the office building are from
the façade on average, the smaller the risk of glare due
to daylight. The calculated percentage of the time that
the UDI value is above 3000 lux is therefore multiplied
in the web application by a factor that depends on the
distance from the façade.
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Factor for distance to façade for calculating the productivity effect of glare
Factor
two desks or fewer 1
three desks or more 0.83
There is a reduction in the effect if the distance is for three desks or more. The
percentage of the time is then multiplied by the productivity effect of 3.5%.
Productivity effect per façade:
PV(façade) = -3.5% * amount of time with daylight > 3000 lux * building factor
View out and daylight
Having a view and daylight both influence productivity positively. In other words, no
view or daylight (or a poorer view/less daylight) can reduce the theoretical productivity
potential in the model by up to 3%.
The parametric model identifies what the risk is for each façade of having no view or a
reduced view, compared to the baseline situation where there are as few obstructions as
possible to let daylight in. The parametric model uses a number of outcomes for this:
- LTA value of chosen shading and/or blinds.
- LTA value of glazing.
- % of the time that the sun and/or daylight shading systems are in use.
Post-processing is then done in the web application again as using shades and blinds
reduces the view and amount of daylight. The model uses the extent to which the LTA
is reduced compared to ‘standard’ glazing to calculate the degree of view/daylight
reduction. This calculates the yearly average LTA value during the period of use:
Yearly average LTA = LTA shading * %time in use + LTA glass * (1 – %time)
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The amount of view and daylight generally depends on the following building
characteristics:
- The percentage of glass in the façade (low/average/high); the more glass in the
façade, the more view and amount of daylight.
- The distance of the desks to the façade (two desks or fewer/three desks or more);
the closer the working area is to the façade, the more view and amount of daylight.
It assumes that the view and daylight exposure decrease by 1/6 when the percentage
of glass drops (for each category) and when the distance to the window increases
(1 = the most view and daylight). Six building factors are known to influence the
amount of view and daylight.
Building factors for view and daylight based on building characteristics
2 desks or fewer 3 desks or more
Not much glass 60% 1.00 0.83
Based on a literature study 1101 , the potential productivity loss due to reduced view
and daylight is estimated at 3.0%. The theoretical production loss per façade is thus
calculated according to the formula:
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Influencing by the individual
Individual people’s opportunities to influence the indoor environment help to improve
satisfaction and productivity. With full individual freedom to influence the solar and
daylight shading systems, the model calculations use a productivity effect of 1.2%.
The degree of individual influencing opportunities due to the presence of systems with
manual and automatic operation depends on:
- The percentage of the time that the sun shines on the façade and the user
therefore has the opportunity to influence the indoor environment by using the
sun and/or light shading devices. Basic principle: solar radiation incident on the
façade > 150 W/m2 (outcome of the parametric model).
- The number of people who work together in the same room: the more people
there are together in one room, the smaller the individual scope for influencing
(it becomes a joint decision).
- The presence of dynamic daylight and/or sun shading; the influencing
opportunities are the greatest when the user has access to both light
shading and solar shading. When there is only one of the two, the influencing
opportunities decrease somewhat.
The influence of the number of people and availability of dynamic sun or daylight shading
systems are included as post-processing in the web application according to several factors.
Combined factor for the influencing opportunities
Number of people in one working area
Presence of both sun
and daylight shading
Presence of either sun
or daylight shading
No sun or daylight
shading
1 person 1 0.75 0
2-3 people 0.8 0.60 0
4-8 people 0.65 0.49 0
>8 people (large open working areas) 0.5 0.38 0
The productivity loss due to the lack of influencing opportunities with respect to the
ingress of sunlight and daylight is calculated per façade. The basic principle is that
the optimum situation serves as a baseline (0% production loss if both sun and light
shading are used when one person is working in a room).
Productivity effect per façade: PC = -1.2% * (1 - control factor) * time of sun on façade
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Office building: calculation of overall productivity effects and payback period
To calculate the average annual productivity effects and payback period, the
outcomes for the individual indoor environment parameters must be post-processed
in the web application.
Average building
Based on the calculations, the theoretical productivity effect due to the influence of
the intervention can be estimated for each indoor environment parameter (Px) for the
entire building. In the calculations, the weighted average of the effect for each façade
must be calculated.
The annual average potential productivity effect for the four orientations must be
multiplied by a factor giving the distribution of staff over the façades (employee
percentage for each façade = EP):
Annual avg. productivity effect = %EPnorth* Pxnorth + %EPeast*
Pxeast + %EPsouth* Pxsouth + %EPwest* Pxwest
Average productivity effect parameters
To calculate the total productivity potential for the chosen intervention, the individual
productivity effects (parameters) should be added up. Because a productivity reduction
due to one of the parameters could affect the relative influence of the others, a
correction for this should be made in the calculation. This correction is an assumption
based on an article by Oseland & Barton (2012) 1104 that compares the results of the
three multi-factor studies. The comparison resulting from this is:
Ptotal = PI + ⅔·P2 + ⅓·P3
From this formula it can be deduced that the productivity loss as a result of the first
parameter is included fully, the second parameter is two-thirds included and the third
parameter is one-third included. The following standard assumptions for calculating
concomitant productivity effects are made in the web application:
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- The productivity reduction due to the lack of view because of sun/light shading
never happens at the same time as productivity reduction as a result of
temperature, radiant heat, glare or control through the use of sun/light shading
(compared to the initial situation). No reduction is therefore applied for the view.
- Productivity drops due to radiant heat and air temperature are added up without
correction, as both affect the temperature as perceived by the users. The
literature study shows that extreme values cause greater drops in productivity,
at least equal to the sum (PTS = PT + PS).
- The weighting factors are used in the same order as the sizes of the effects. The
largest reduction factor is used on the smallest productivity effect. Example: If
PTS > PV > PC applies in a situation: Ptotal = PU + PTS + ⅔ PV + ⅓ PC.
This total should then be multiplied by the percentage of the time that staff work at
their office workstation on average (i.e. not offsite or at home):
Ppotential total = PTotal * % of work done at office workstation
The value of the productivity potential can now be calculated based on the revenue or
total costs associated with the staff members, depending on the type of organisation.
In cases of a company or organisation operating to make a profit, the productivity
potential per year (in euros) is calculated by multiplying the productivity potential total
(%) by the revenue (in euros).
In cases of non-profit companies or organisations, the productivity potential per year
(in euros) is calculated by multiplying the productivity potential total (%) by the total
annual personnel costs in euros.
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Influences on indoor environment parameters
Temperature
To compare the extent to which the chosen interventions help prevent excessive
temperatures, the hourly average temperatures were compared against the class
A, B and C upper temperature limits from the Programme of Requirements (PoR)
for Healthy Offices 2021.
For each class (A, B and C), the number of exceedance hours per year during the
periods of use was calculated. The results have been broken down by season to show
when the dynamic shading is most effective at preventing overheating.
Calculated number of overshoot hours per class and per period for each model*
Class C Class B Class A
27°C 26°C 25°C
Year
Winter
Spring
Summer
Autumn
Based on the number of exceedance hours, the class (for temperature in the summer)
from the Programme of Requirements that the situation complies with is also
calculated. The requirement is that the limit value for the class in question must be met
at least 95% of the time.
Radiation temperature
To what degree direct sunlight falling on a person affects their temperature perception
is defined using the ΔMRT as calculated, including the building factors. The perceived
temperature difference as a result of radiation on the body = ½ * ΔMRT.
Seasonal average radiation temperature due to direct sunlight falling on a person*
Avg. perceived temperature difference
resulting from radiation falling on the body
Winter Spring Summer Autumn
*The tables have only been included to clarify the text and the numbers were deliberately omitted
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Glare
When determining the influences of dazzling, the risk of glare plays a key role. In
practice, the risk of glare due to daylight (daylight glare probability or DGP) depends on
the position and the line of sight.
However, the model uses a different method and metrics, because the DGP calculation
only looks at one viewing direction. Moreover, the computing capacity needed for
calculating all possible variants is too high. To get a picture of the risk of glare in the
room as a whole, the UDI (useful daylight illuminance) is used.
For all possible combinations of reference model and intervention, a calculation was
made of the percentage of the time (during a period of use) when the UDI value was >
3000 lux (for at least 50% of the floor surface area). In these cases, it was assumed
that there is a risk of glare due to the bright daylight. Based on that, the influence can
be expressed as a formula:
Risk of glare = %time with UDI > 3000 lux (for at least 50% of the floor area)
Daylight
For daylight, the percentage of the time when the light intensity is at least 300 lux due
to the ingress of daylight is shown. The effects of incoming sunlight and solar shading
are also included here. To test whether enough daylight gets into a building, this model
uses a method called Spatial Daylight Autonomy (sDA).
This is a standardised method developed by the Illuminating Engineering Society (IES)
that determines what levels of daylight the indoor environment has. The sDA shows
what percentage of an area being analysed (in this case the room in the office building)
achieves a minimum light intensity due to daylight (e.g. 300 lux) during all or 50% of
the operating hours. Given that it is a standardised calculation that is used to give
a clear picture and compare the quality of daylight globally, the operating hours are
determined for the interval from 08:00 to 18:00, including weekends.
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Influencing opportunities
To map out the level of opportunities to influence the environment using dynamic solar
and daylight shading, the possible options are categorised on a five-point scale:
1. No control of daylight and incoming sunlight.
2. Little control of daylight and incoming sunlight.
3. Some control of daylight and incoming sunlight.
4. Reasonable degree of control of daylight and incoming sunlight.
5. High degree of control of daylight and incoming sunlight.
Score on a five-point scale for daylight and incoming sunlight
Number of people in one working area
Presence of both sun
and daylight shading
Presence of sun or
daylight shading
No sun or daylight
shading
1 person 5 5 1
2-3 people 5 4 1
4-8 people 4 3 1
>8 people (large open work areas) 3 2 1
Visualisation of the outcomes
A conscious decision was made to visualise the outcomes of all calculations, for two
reasons:
- This makes it easier to discuss the outcomes of all calculations with decisionmakers
and influencers.
- Visualisation like this creates more opportunities for presenting the situation to
owners and users on a more permanent basis in the form of a cockpit.
The outcomes in the pathway for the decision to use dynamic solar and light shading
solutions can be visualised using the web application.
The structure of the application is set up as follows:
Input
The web app user enters the building characteristics from a 3D model and specifies the
desired interventions (sun and daylight shading systems).
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Processing data in the application
Performance figures for energy, productivity and the indoor environment parameters
are worked out. To calculate the results, the application retrieves the data and does
post-processing based on the project-specific input.
Output
The outcomes that are relevant for the user are presented in the application. This gives
a picture of the impact of using the chosen sun and daylight shading solutions on the
productivity potential, energy performance, indoor environment and payback period.
The structure of the outcomes is displayed as KPIs in the scheme outlined below.
Overview
Key Performance Indicators (KPIs)
Productivity Energy Indoor environment ROI
Main page
theme
Productivity
overview
Energy
overview
Indoor environment
overview
ROI overview
Subtheme
Productivity
per parameter
Energy per
component
Performance per
parameter
Outcomes per
component
Detailed display
Detailed
performance
Most important key performance indicators
Four KPIs were chosen as the most important outcomes:
- Productivity potential total in % (difference between intervention and reference),
- Reduction of CO2 emissions in kg/m2 (difference between intervention and reference),
- Class for temperature in the summer, as per the Programme of Requirements for
Healthy Offices - indoor environment (intervention),
- Return on investment in % (intervention),
The web application then gives you the option of looking at the information for all
themes in greater detail.
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Productivity effect
The main page for productivity shows the productivity potential after applying the
intervention. The effects are broken down by indoor environment parameter.
The relevant productivity subthemes can then be detailed further:
- Temperature: productivity potential (caused by the air temperature).
- Radiation: productivity potential (caused by the air temperature).
- Glare: productivity potential (caused by dazzling).
- View out and daylight: productivity potential (caused by the view out and daylight).
- Influencing opportunities: productivity potential as a result of the opportunities
to influence the shading.
The annual average productivity effect resulting from each theme is shown for the
reference, the intervention (variant 1) and the “gain” (difference between intervention
and baseline). It is possible to add an extra variant to compare the effects of different
interventions.
Productivity subtheme: productivity effect of air temperature
Energy performance
The main page shows the reduction in CO2 emissions after applying the intervention,
broken down into the effects resulting from cooling, heating and the total.
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Main energy performance page
The subthemes for energy are:
- Energy: energy use in kWh/m2 for each season.
- Cooling: energy use for cooling in kWh/m2 for each season.
- Heating: energy use for heating in kWh/m2 for each season.
- Comfort: number of exceedance hours w.r.t. the class B requirements from the
Programme of Requirements for Healthy Offices, for each season.
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An example display for the subthemes ‘Energy’ and ‘Comfort’ is given below. For all
subthemes, the option of adding the outcomes of the reference and any other variants
can be offered so that they can be compared.
Example of a more in-depth look into the subtheme ‘Energy’
Example of a more in-depth look into the subtheme ‘Comfort’
Indoor environmental performance figures
The main page for productivity shows the productivity potential after applying the
intervention. The effects are broken down here for the relevant indoor environment
parameters.
Main page for indoor environmental performance figures
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These indoor environment themes can then be specified further.
The subthemes for productivity are:
- Temperature: exceedance hours of temperature limits for classes A, B and C.
- Radiation: increased temperature caused by solar radiation falling on the body,
for each season.
- Glare: percentage of the time that there is a risk of dazzling.
- View out and daylight: percentage of the time that enough daylight gets in.
- Influencing opportunities: score for the opportunities for influencing solar
radiation and daylight ingress.
The outcomes of the intervention in each theme are displayed and compared against
the reference baseline, showing the differences. The option of adding an extra variant
(if created) can also be offered here to compare the effect of different interventions.
Indoor environment subtheme: temperature performance figures
The detail pages then give a picture of the outcomes for each façade orientation. There
are detail pages for the air temperature, glare and daylight:
- Temperature: this specifies the exceedance hours for all classes in each season, both
at the building level and for each façade orientation (a separate graph for each),
- Radiation: increased temperature resulting from solar radiation falling on the
body for each season for the various façade orientations (graph for each),
- Glare: the risk of dazzling is shown for each façade in a figure for the reference
(baseline) and the situation with the chosen variant. When opting to use both
solar and daylight shading for a single façade, figures are shown for each (with
solar and light shading solutions),
- Incoming daylight: the ingress of daylight for each façade in a figure (one page
for each) for the reference (baseline) and the chosen variant.
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- Influencing opportunities: score for the opportunities for influencing solar
radiation and daylight ingress for each façade (all in a single graph).
Detail page for temperature exceedance hours specified by season and class (example:
average value for the building)
Detail page for the risk of glare in the room for each orientation of the façade
ROI and payback period
The productivity main page shows the return on investment (ROI) given the expected
effects on energy and productivity. Additionally, the payback period (PP) is also shown,
as are the costs and the budget.
Main page for the ROI and payback period
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These themes are then worked out in more detail in subthemes:
- Return on investment (ROI): ROI total and a breakdown for energy and
productivity.
- Payback period (PP): PP total and a breakdown for energy and productivity.
- Costs: the costs for the interventions in total and for each component (daylight
shading, interior solar shading and exterior solar shading solutions),
- Investment budget: the calculated savings on the energy costs, the productivity
potential and the total.
Comparing variants
The web application also offers the option of comparing different variants by saving
a created variant and comparing it against an alternative variant. To that end, the
application has the option of putting the outcomes of the different variants side by side
to let you see the differences graphically.
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1101 “bba literatuuronderzoek productiviteit - Somfy" of 17-Jun-2020.
“Somfy productiviteitstool DEF” of 20-Oct-2020.
1102 Arens et al., (2018} Sunlight and indoor thermal comfort- Update to Standard 55,
ASHRAE Journal July 2018
1103 https://comfort.cbe.berkeley.edu/
1104 Oseland, N., & Burton, A (2012). Quantifying the impact of environmental
conditions on worker performance for inputting to a business case to justify
enhanced workplace design features. Journal of Building Survey,
Appraisal & Valuation, 1(2), pp. 151-165..
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226

APPENDICES
227

APPENDIX 1: QUESTIONNAIRE
To enable calculation of the productivity potential in a building the following questions
should be answered in the tool. The questions are divided into several categories:
I. Building characteristics
II. Productivity effect value
III. Intervention to be applied
IV. Investment
I. Building characteristics
1. What is (roughly) the percentage of glass surfaces in the façade for which solar
and/or daylight shading is installed?
a. Low use of glass < 30%
b. Average 30 to 60%
c. High use of glass > 60%
2. Has reflective glazing been applied for the building?
North: yes no
East: yes no
South: yes no
West: yes no
3. What is the (global) division of workstations across each façade?
North: %
East: %
South: %
West: %
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4. How many desks are positioned next to each other, perpendicular to one façade?
a. 2 desks
b. At least 3 desks
5. How many people typically work together in one single space?
a. 1 person
b. 2 to 3 persons
c. 4 to 8 persons
d. > 8 persons (large open-plan spaces)
6. Are there any cooling facilities in the building?
a. Cooling is available
b. Only top-cooling
c. No cooling
7. What percentage of the time is work (generating the turnover) effectively
carried out at the work place in the building?
% of the time that work is carried out at the office workplace
(not at home or outside of the workplace)
II. Productivity effect value
8. Does the vast majority (> 90%) of the staff work at the office?
yes
no
If question 8 is “No” continue with question 9a. If question 8 is “Yes” continue with question 9.
9. How many FTEs do you employ? FTEs
After question 9 continue with question 10
9a. How many FTEs do you employ in total? FTEs
9b. Of these, what percentage consists of office workers? %
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For the following questions please enter the data for the organisation as a whole
10. Do the staff work for a company or organisation operating on a profit-making basis
(e.g.: SMEs “yes” and government institution “no”)?
yes no If question 10 is “No” continue with question 12.
If question 10 is “Yes” continue with question 11.
11. What is the annual turnover of the applicable department/organisation?
in millions of euros
Default value: 350,000 euro/FTE
12. What are the total annual costs per FTE? (Determine the total annual expenses and
divide that number by the number of FTEs (labour costs, accommodation costs,
etc.))
in euros Default value: 75,000 euro/FTE
III. Intervention to be applied
13. Apply daylight shading to:
North: yes no
East: yes no
South: yes no
West: yes no
14. Apply solar shading to:
North: yes, outdoor solar shading yes, indoor solar shading no
East: yes, outdoor solar shading yes, indoor solar shading no
South: yes, outdoor solar shading yes, indoor solar shading no
West: yes, outdoor solar shading yes, indoor solar shading no
15. Apply individual control and automatic control to solar shading.
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IV. Investment
16. What is the total surface of glass per façade?
North: m 2
East: m 2
South: m 2
West: m 2
17. What are the costs per m2
Daylight shading €/m 2
Indoor solar shading €/m 2
Outdoor solar shading €/m 2
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APPENDIX 2: BUILDING CHARACTERISTICS OF THE
‘STANDARD OFFICE SPACE’
This appendix describes the assumptions and characteristics for the ‘standard office space’ used in
the calculations.
Parametric model
Various software packages and plug-ins were used
for the model and calculations. The spatial model was
displayed in a modelling environment called Rhino 3D.
A software package for visual programming
(Grasshopper) makes it possible to carry out parametric
operations. The Ladybug Tools plug-in was used for
doing the calculations. The last of these plug-ins makes
it possible to carry out and combine both energy and
sunlight/daylight studies.
The computing core programs used for energy and
daylight are EnergyPlus and Radiance; both these
products come from the United States Department of
Energy. These computing cores are used worldwide in
both open-source and commercial software programs.
An IWEC climatological file was used for the various
calculations (IWEC stands for International Weather for
Energy Calculations). These files are available from the
ASHRAE database. The reference year is constructed
using measured data from previous years.
Illustration of the calculation model and visualisation of the result.
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General description of the model structure
The first step in the model is creating a spatial model (and
parameterising it). This involves modelling six surfaces.
Various properties are then assigned to those surfaces:
- Adjacent structure (ground, outside air,
an identical space, etc.).
- Structural properties (material layers,
insulating and reflecting properties).
- The presence or otherwise of a window
and the properties of the glass.
Additional properties are then assigned to the space,
such as:
- Shading, with associated characteristics and
control strategies.
- Assumptions about the room temperature,
heating/cooling.
- Assumptions about the space: number of people,
lighting, equipment, ventilation, infiltration, etc.
- Diagrams and usage times for the assumptions
mentioned above.
- A concept for the installed systems, including the
heating and cooling capacities.
For the energy component, the post-processing then
looks at the hourly average values for:
- Heating and cooling demand.
- Air temperatures and numbers of hours during
which the limits for classes A, B or C are exceeded.
- Radiation temperature.
- Operative temperature (an average of the radiation
temperature and the air temperature).
- PMV exceedance due to incoming solar radiation
falling on the body.
The heating and cooling demand shows how much
cold and heat are required at the level of the individual
room. This is not the same as the capacity supplied by
a generating system such as a central heating boiler,
cooler, heat pump or whatever.
That is adjusted in the post-processing. At this point, the
type of generating system that is present in the building
is defined, along with the efficiency of this source
of heat or cold. That determines the ultimate energy
consumption of the office unit. Various guideline values
that can be used for inputting the efficiency figures are
given below.
In the structural model, the properties for an energy
calculation and a daylight calculation are linked together.
This information is in turn linked to the computing core,
which runs a calculation or simulation of an entire year.
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Overview of guideline efficiency figures
Heating
Cooling
Installation COP (coefficient of performance) Installation EER (energy efficiency ratio)
Central heating boiler 1 Cooling unit (low temperature) 3
Air/water heat pump 4 Air/water heat pump (high temperature) 4
Water/water heat pump 5 Free cooling (closed source) 10
Free cooling (open source) 16
For the daylight component, the output for each measured point is the amount of
incoming solar radiation per hour of the year. This applies to scenarios both with and
without sun shading. Depending on the control strategy, the desired results are produced
in post-processing. The results produced in post-processing include:
- Amount of energy falling on the façade.
- The number of hours that the shading device is down for.
- Daylight quality (sDA),
- Risk of glare (UDI).
In addition, the results of the above-mentioned calculations also allow the requisite
productivity parameters to be determined based on the assumptions in the model.
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General features and usage of the office space:
Dimensions
Width: 3.6 metres
Length: 5.4 metres
Height: 2.7 metres
Building construction
Internal wall (Rc value 2.0 m2 • K/W):
Plasterboard 2 x 12.5 mm
Insulation 75 mm
External wall (Rc value 4.7 m2 • K/W):
Outer envelope masonry
Cavity
180 mm rock wool
Sand-lime brick inner shell
Thickness of exterior wall: 400 mm
Ventilation
Basic ventilation: 40 m3/hour per person (class
B of the Programme of Requirements for Healthy
Offices) from 07:00 to 19:00
Air infiltration: 0.0003 m3/s per m2 façade at a
pressure difference of 4 Pa.
Usage time of building/room
Hours in use: from 07:00 to 19:00, 5 days a week
(1 January to 31 December).
Internal heat burden
People (120 watts per person)
2 people per office 07:00 to 19:00
Laptop (100 watts) 07:00 to 19:00
Lighting (5 W/m2, assuming LED lighting)
Window (Uw value for the window: 1.65 W/m2 • K):
Frame
HR++-glass (solar control glazing or otherwise)
ZTA value 0.3 or 0.6, depending on the calculation
Floor/ceiling (Rc value 2.5 m2 • K/W)
Linoleum
50 mm floor layer
70 mm floor topping
270 mm concrete (hollow-core slab floor)
Cavity
Acoustic ceiling
Heating
Air heating, unlimited capacity.
Variable building characteristics
In the model, the following building characteristics that
influence the calculated indoor environment and energy
performance are variable and depend on the user input.
Orientation of the building/the office spaces.
Percentage of glass in the façade.
With solar control glazing per façade.
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Percentage of glass in the façade
Little glass: < 30% (a glass percentage of
25% in the model)
Average: 30% to 60% (a glass percentage of
50% in the model)
A lot of glass: > 60% (a glass percentage of
80% in the model)
With solar control glazing
Solar control glazing: g-value 0.3
Standard glazing: g-value 0.6
Cooling
None: 0 W/m2
Top cooling: 30 W/m2
Full cooling: 60 W/m2
The capacity of top cooling was determined on the
basis of practical experience. Threefold or fourfold
ventilation is used to provide top cooling for a room.
For full cooling, the assumption is a system with a
climate-control ceiling, ceiling induction units or fan
convectors. The lifting capacity stated is the upper
limit of the deliverable capacity of these systems.
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APPENDIX 3: FEATURES OF INTERVENTIONS
Features of solar and light shading
The following table lists the features of various sun and daylight shading systems.
Based on the properties of various sun protection fabrics as supplied, the
following have been adopted as reference fabrics and included in the calculation:
Characteristics of interventions when used with ‘normal’ glazing
and solar-control glazing
Intervention
Indoor shading,
metallised
Pale-coloured
shading (outside)
Dark-coloured
shading (outside)
Type
Verosol
OmniaScreen 293
FD-01
Verosol Originals
816 - 000
Pure black cloth
(Sergé 3% Black)
Thickness
in mm
Transmission
of solar
radiation
Reflection of
solar radiation
on the outer
surface
Openness
factor
0.58 0.06 0.74 0.03
0.20 0.29 0.44 0.23
0.44 0.03 0.04 0.03
Daylight shading Coulisse Paris 0.47 0.40 0.56 0.03
Dynamic control
Controller (automatic) option 1
- Automatically controlled shades
- Down when incoming solar radiation is > 150 W/m2
- Up when incoming solar radiation is < 150 W/m2
Controller (automatic) option 2
- Automatically controlled shades
- Down when incoming solar radiation is > 300 W/m2
- Up when incoming solar radiation is < 300 W/m2
Control dependent on the external temperature
Controller (automatic) option 1
- Automatically controlled shades
- Down when incoming solar radiation is > 150 W/m2 and outside temp. is > 15°C
- Up when incoming solar radiation is < 150 W/m2
Controller (automatic) option 2
- Automatically controlled shades
- Down when incoming solar radiation is > 300 W/m2 and outside temp. is > 15°C
- Up when incoming solar radiation is < 300 W/m2
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APPENDIX 4 ASSUMPTIONS FOR
PRODUCTIVITY EFFECTS
To calculate the influence of solar radiation on lightness, values are assumed
for the proportion of the sky that is visible from the workplace and for the
proportion of the body that is exposed to sunlight. These values depend on the
building characteristics (distance of working area to the façade and the glass
surface): the influence of radiant heat on the sensation of warmth decreases
the further from the façade you are (distance between working area and
façade). Moreover, the influence is smaller when the glass surface is smaller
as there will then be less exposure to sunlight. The values to use for this were
based on ASHRAE-55 and are specified further in the tables below.
Parameter 4: Proportion of the sky visible from the user’s position, based on
ASHRAE-55 and depending on the percentage of glass in the façade and
distances of the workplaces from the window
2 desks or fewer 3 desks or more
Little glass, 60% 0.3 0.2
Parameter 5: Proportion of the body exposed to sunlight,
based on ASHRAE-55 and depending on the percentage
of glass in the façade
Exposure (-)
Little glass, 60% 0.7
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12
SUSTAINABILITY AS THE TOP PRIORITY
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EU TAXONOMY
With an eye on achieving the EU’s climate and energy targets, it is vital that investments should
target sustainable projects and activities. This needs a methodical approach and a clear definition
of what sustainability means. In this context, work has been done on an action plan for funding
sustainable growth and on introducing a common classification system for sustainable economic
activities, known as the EU taxonomy.
The EU taxonomy is a classification system for a list of
environmentally sustainable economic activities and it
is intended to play a major role in scaling up sustainable
investments by the EU and the implementation of the
European Green Deal.
The EU taxonomy should give businesses, investors
and policymakers appropriate definitions of economic
activities that can be deemed environmentally sustainable.
This should create certainty for investors, protect
consumers from greenwashing, help companies become
more climate-friendly, reduce fragmentation in the market
and help shift investments to where they are most needed.
The Taxonomy Regulation was published in the Official
Journal of the European Union on 22 June 2020 and it
came into force on 12 July 2020.
Under the Taxonomy Regulation, the European
Commission had to draw up not only the actual list
of environmentally sustainable activities but also
technical criteria for each environmental goal.
An initial act was adopted in principle on 21 April 2021
and formally adopted on 4 June 2021 for review by the
co-legislators; these were about sustainable activities
relating to mitigating climate change and adapting to it.
The publication of the first delegated act
was accompanied by guidelines for the EU taxonomy,
guidelines for sustainability reporting for companies
and guidelines for using funding to achieve the
European Green Deal goals.
On 6 July 2021, the Commission further specified
the underlying methodology and presentation of
information to be disclosed by financial and nonfinancial
corporations about the proportions of
environmentally sustainable economic activities in
their businesses, investments and lending activities.
This meant that companies could no longer sit and
do nothing. National legislation will be amended and
the entire financial sector will be utilised to drive the
economy in the appropriate direction.
Banks, pension funds, insurers and asset managers
in the Netherlands therefore need to have stated
by 2022 at the latest how they are going to reduce
the CO2 footprints of their portfolios by 2030. From
2020 onwards, the financial sector institutions in
the Netherlands have been required to report the CO2
emissions of loans and investments. In addition, fifty
businesses from the financial sector in the Netherlands
have signed a covenant underpinning the principles and
the cooperation needed to attain a sustainable society.
Together, the institutions represent investments worth
€3,000 billion.
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The financial sector is applying the CO2 emission
reduction principles to business customers but
the scope also covers the financing of privatelyowned
properties.
Financial institutions naturally do not want to run the
risk of being lumbered with loans that companies
default on because they are put out of business as a
result of the transition. Banks will also want to ensure
in good time that properties used as collateral for
financing meet the standards.
Unsustainable portfolios of mortgages and other loans
do not help financial institutions achieve their own
sustainability goals, as well as representing an everlower
value.
Greenwashing
Greenwashing means a company or organisation
faking being greener or more socially responsible than
it actually is, by pretending to deal sensibly with the
environment and/or other social issues.
Not every organisation that commits greenwashing
does so deliberately. In many cases, people want to
act socially responsibly but fail to realise that the
company’s core processes also need to be adapted
if they are to become genuinely socially responsible.
So greenwashing is sometimes the first step towards
genuinely socially responsible policies.
For commercial properties, the legislation stipulated
several years ago that offices must have at least
energy label C by 2023, with the potential penalty of not
being able to use such premises any longer. Legislation,
too, is moving towards sustainability.
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244

RODERIK
HENDERSON
As part of our study, which focuses on buildings, we asked Roderik Henderson to create a photographic
anthology of developments in the architecture of office buildings in the Netherlands from roughly the last 30 years.
So he travelled through the Netherlands armed with his inseparable backpack filled with his tools
of the trade and that has now yielded a series of nearly 15,000 photographs.
That material has all been produced in the last three months and the number of photos will undoubtedly grow
yet further. Time has been too short to classify everything neatly and study it in greater detail. We thought it
would be nice nevertheless to add a very small and fairly randomly chosen selection to this issue.
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The photographer Roderik Henderson (b. 1965)
and his wife Tanja roamed the southwest of the
United States for many years. They crisscrossed
the desert in a Jeep Wagoneer that wasn’t exactly
in the first flush of youth plus a small Airstream
Argosy caravan. “Hunting for the brightness of
bare rock, burning sand and deafening silence.
Unthinking, dreamless, with no ambitions – just
total, phenomenal emptiness. Salt flats and lava
beds were our home.”
After spending a couple of winters in the Canadian
wilderness, Roderik and his wife – now accompanied
by two children – set off again in January 2010 on
an existential, artistic trek through Chile.
Roderik was a winner in the 2010 World Press
Photo Awards, claiming first prize in the Portraits
category. Roderik was also nominated for the 2020
Somfy Photography Award. He recently relocated
to the Netherlands.
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Somfy Nederland BV
Jacobus Ahrendlaan 1
Postbus 163
2130 AD Hoofddorp
The Netherlands
Phone +31 (0)23 55 44 900
info.nl@somfy.com
www.somfy.nl
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