PUSHING THE ENVELOPE - Dansk Arkitektur Center

PUSHING THE ENVELOPE
TWO-DAY MASTERCLASS ON THE FUTURE OF
FACADES
TO DAGES MASTERCLASS OM FREMTIDENS
FACADE

© 2010 Dansk Arkitektur Center
Udgivet med støtte fra Realdania
Tekst: Christian Bundegaard
Layout: Heidi Pedersen, Christensen & CO arkitekter
Designkoncept: Lene Sørensen Rose
Master class foto’s: Nanna Gyrithe Jardorf, Heidi Pedersen
Cover photo: © James Ward & Arup Associates
Tryk: Grefta Tryk
© 2010 Danish Architecture Centre
Published with support from by Realdania
Text: Christian Bundegaard
Layout: Heidi Pedersen, Christensen & CO architects
Designkoncept: Lene Sørensen Rose
Master class photographs: Nanna Gyrithe Jardorf, Heidi Pedersen
Cover foto: © James Ward & Arup Associates
Print: Grefta Tryk
www.dac.dk

CONTENTS
04 INTRODUCTION
NATALIE MOSSIN
07 MASTERCLASS REPORT
CHRISTIAN BUNDEGAARD
26 FAÇADE REFURBISHMENT
– WHAT IS THE POTENTIAL ?
ANNE BAGGER
28 THE SOLIDS
JESPER NIELSEN
30 NEW PERSPECTIVES ON FAÇADE REFURBISHMENT
ULRICH KNACK
32 THE DECADE OF THE FAÇADE ENGINEER
MIKKEL KRAGH
34 NEW MATERIALS
MARCEL BILOW
36 NEXT ACTIVE FAÇADES
TILLMANN KLEIN
38 PREFABRICATION AND THE CARE FOR DETAIL IN
REFURBISHING EXISTING FAÇADES
STIG MIKKELSEN
40 INTELLIGENT BEHAVIOUR
ALEXANDRA THYGESEN
42 DANISH SUMMARY
CHRISTIAN BUNDEGAARD
44 PARTICIPANTS
47 ACKNOWLEDGEMENT

INTRODUCTION
Natalie Mossin
Specialist, Innovation in Construction
Danish Architecture Centre
From 2005 through 2008 Realdania
supported the implementation of
a range of development projects
aimed at strengthening innovation
in construction through the initiative
Building Lab DK, a division of the
Danish Architecture Centre. But
while the initiative is completed – the
development projects live on - and the
interest in innovation and the passion
to translate this into practice is
undiminished among the researchers
and practitioners who worked on
Building Lab DK supported projects.
The vibrancy of this informal network
of professionals committed to
innovation is what has lead to the
masterclass “Pushing the Envelope”
and to this publication. The master
class was arranged by DAC in
collaboration with CINARK, DTU Byg
and CCO and its purpose has been
to provide a platform for agents of
change to meet and exchange ideas.
The master class brought together
specialists and professionals with a
specific interest in façade-engineering
from across business and research
institutions..
The purpose was to facilitate a debate
on the future of existing facades and
to develop innovate ideas to the
renewal of underperforming facades.
The debate examined the most
important problems, ideas and
drivers in the development of
sustainable façade systems for
existing buildings, and identified key
components in how we might reap
the potential inherent in renovation
- technically as well as architecturally.
This publication presents the debate
as it took place as well as a range
of specialist viewpoints on the
development of façade solutions
for existing buildings. It is our
hope that it will be of inspiration
to others, who has a stake in, and
the courage to take ownership
of, the future of existing facades.
The Danish Architecture Centre
continues to focus on new
understandings of construction and
the dissemination of experience,
methods and prospects for
construction operators.
5

The master class took place over two days in September, 2010 at the Royal Danish Academy, School
of Architecture in Copenhagen, Denmark.

MASTER CLASS REPORT
CHRISTIAN BUNDEGAARD
"Masterclass" the organizers called
the seminar. "Because all those
participating are the masters in this
field," said Natalie Mossin from the
Danish Architecture Center in her
welcome speech. And there were
good reasons behind gathering this
brain trust a few sunny, late summer
days at the School of Architecture in
Copenhagen. The topic was a truly
important one for the future of the
building industry in its global context
of climate change and the need for
energy saving solutions: the façade,
- with a special focus on existing
buildings and refurbishment.
Envelope Innovation Needed.
Façades are much more than just
the faces of buildings. The façade
is the membrane between the living
or working space of the interior and
the forces of nature itself. But with
the looming threat of disruptive
climate changes it is essential that
buildings, as one of the major
energy consumers, are developed
and transformed in a sustainable
direction.
Therefore it is imperative that façade
specialists exchange views on how
to be innovative in developing
tomorrow's façades. The building's
skin contains a high potential for
sustainable solutions. These are
complex matters, however, which
include a diverse range of aspects
such as future technologies, new
materials, indoor climate, human
behavior, architecture and economics.
Further, the solutions that are to be
found must be simple enough to allow
profitably production, and persuasive
enough to convince a conservative
building industry and their final users,
who might rather spend their money
on a new kitchen. Hence, the need
for research, thinking out of the box
and the free exchange of ideas.
Therefore, a master class, trying to
“push” the building envelope.
The development of innovative
solutions might be a challenge
in new constructions, but at least
that situation offers a clean slate.
When dealing with existing buildings
several aspects have to be taken
into account. On one the hand,
there is a substantial need for
renovation and updating of millions
of homes and office buildings with
inadequate insulation and outdated
functionalities, in a sometimes quite
poor design. On the other, however,
many buildings of a poor insulation
standard represent interesting and
robust architectural value. Here, there
is a need for renewing and preserving
at the same time.
My favorite façade.
For a start, all participants were
asked to name af façade they had
worked on or one they simply liked.
Mikkel Kragh from Arup had helped
to create the Danish Pavilion for Expo
in Shanghai and was quite proud of a
façade with no mechanical parts. Stig
Mikkelsen from Dissing + Weitling
recalled his practice’s heritage from
Arne Jacobsen’s studio and what was
possibly the first double-skin façade
on Danish soil, Jacobsen’s building
for Denmark’s National Bank.
Thomas Bo Jensen could not help but
point to another Danish classic, the
building he himself had written his
thesis on, a house made of five million
parts, namely PV Jensen Klint´s brick
cathedral, Grundtvigskirken. Also,
Jean Nouvel’s Arab Institute in Paris
was mentioned, and the Danish neo-
modern icon power-station opposite
of Magasin du Nord in Copenhagen.
Another participant would, rather
than to name a single façade,
choose the optional principle: User
configurated solutions like
in the case of balconies from altan.dk.
And finally, one participant pointed to
his windbreaker made of Goretex as
the perfect envelope - weatherproof,
flexible and attractive to look at.
The two day seminar was structured
around short presentations with
opportunity for discussion, giving way
to group sessions around a series of
specific tasks. The six presentations
are reprinted in this publication, so
below is the primary fracture surfaces
7

8
in the discussions and the recurring
themes and (preliminary) conclusions
that will be discovered.
Potentials in refurbishment.
Postdoctoral Fellow Anne Bagger’s
Introduction to the potentials
for saving energy by renovating
old buildings prompted a lively
discussion. These potentials are
not to be underestimated. Even in
Denmark, which is one of the places
where energy saving in buildings has
been an issue for decades, windows
with high u-value and walls without
insulation abound. As Anne Bagger
herself asked, if at the same time
the indoor climate can be bettered
and energy can be saved, why is not
sustainable refurbishment flowering?
Well, for one thing, private homes
tend to be owned by people! People,
who prioritize differently from the
professionals. Most people find a
new kitchen both more necessary
and more sexy than 300 mm of
insulation. Another challenge is the
“invisibility” energy issues. Many have
their heating bill payed automatically
via internet banking. Finally, there
is the comprehensive question of
everyday habits and behaviour. First
and foremost we live in our houses.
Some people simply might want to
keep their windows open in order to
hear the birds sing. Is this really a
problem? asked Anne Bagger.
In the discussion that followed,
several issues, that should be
recurring during the rest of the
seminar came up. One was the
conservatism of the building industry.
New products like façade elements
with better performance would have
to be produced by manufacturers
that still have to make a profit, and
therefore have to regard what the
craftsmen are used to handle and feel
confident about. Work is carried out
by craftsmen, who are not salesmen,
and have a hard time bringing in new
products. In this way no one, and last
of all the customers, are encouraged
to act differently.
One way out of this vicious circle could
be state support of demonstration
products and projects. This may break
the ice and make new solutions less
adventurous. Often new inventions
are not put into smaller products
but in systems that demand a lot
of resources. Further it is vital to
consider not just the product itself,
but the whole process including
transport issues and maintenance
later on.
Maybe, as Professor Ulrich Knaack
from the Delft University of Technology
(TU Delft) suggested, proponents of
sustainable refurbishment will have
to trigger people to take interest in
solutions put together from kits, or bits
and pieces bought at the bricolage.

Engaging people might be a core
issue, and the dicussion immediately
showed the different stands and
attitudes. Bagger complained that
no consultant normally is around to
tell you how to operate a window,
for example. But does it make any
sense to say that people are not using
buildings the right way, when after all
they are the ones living there, making
themselves feel at home with all their
habits and ways, it was argued.
Stig Mikkelsen reminded everybody
of the challenge of making new
solutions acceptable to the residents,
as it was the common notion that
refurbishments deterioated indoor
climate; and indeed earlier it had
been the case, as people were not
aware how important it was to
operate windows and systems the
right way.
It was quite amazing, Tom Hay
added, that to his experience even
corporate clients did not understand
how buildings work, and secondly,
to the question of aesthetics,
unfortunately great buildings were
very often energy busters. In both
cases it was down to simple things;
people’s behaviour and preferences.
Perhaps the way to “beat the kitchen,”
as it was put, was to make the
envelope more active, more refined
and attractive. Energy features
should be better integrated in the
overall aesthetic approach, and non-
energy features should be made more
outstanding in the product design.
Another route of attaining stronger
engagement could include, as
Emanuele Naboni suggested,
experiments like the ones where
final users in residential community
housing participated in competitions
to save energy and were monitored
in the everyday routines. In this way,
valuable knowledge of behaviour
could be distilled.
Postdoctoral Fellow Anne Bagger, highlighted the need to
acknowledge the habits of the people expected to invest
private funds in the renovation of their homes.
9

Jesper Nielsen, Head of Centre,
CINEARK, outlined the history of
the curtain wall.
10
Refurbishment of the
preservable.
Head of Centre at CINARK, Jesper
Nielsen, outlined the history of the
curtain wall, going back to the first
curtain wall façades of the 19th
Century through the first industrial
façade with the use of aluminium
in 1954. Since then, most of the
development has taken place around
curatain walling. Renovation is easy
and can be done just by changing
the “curtain”.
But then, what about great
architecture like Danish architect Kay
Fisker’s building for Mødrehjælpen
also from the mid-fifties, Nielsen
asked. A beautiful and austere piece
of brickwork architecture with a lot of
meticulously done detailing. Just to
change the balconies, for example,
would completely alter the balance
of the whole.
Almost anything one does will be
wrong; and the radical solution,
where historic buildings are torn
down only to be completely rebuilt
within todays standards, might not
be what you want either. Buildings
that are not listed, but still highly
preservable are a real challenge to
sustainable refurbishment.
During discussion the participants
in the seminar came to several
interesting conclusions. For one
thing, the industry has to expand
its thinking to include other Façades
than the curtain wall. Alternatives
to highly layered membranes would
have to be found.
Marcel Bilow from Imagine Envelope
at TU Delft made the point that the
curtain wall was about to change
radically. In future, less glass would
be needed to achieve the goals of
most concepts; and Mikkel Kragh
added that first and foremost, he was

in fact “obsessed with windows”, but
second, he was convinced that the
question of transparency of façades
was now solved and that it was time
to move on. Some suggested that
a catalogue of technologies fit for
renovation processes should be made
in order to facilitate the refurbishment
of many types of façades. Again, it
was emphasized by several that
refurbishment starts with the people
living in the buildings, and that is
was paramount to include them in
the process. Anja Bache from the
Technical University of Denmark
finally asked for ways to connect the
proof of concept in development of
new materials and solutions with the
refurbishment process.
After lunch Ulrich Knaack took the
floor to draw a rapid roadmap of
the first 12,000 years of building
development, although with a
focus on the last 15 years of
façade development. At the Delft
University of Technology, Knaack
and his team worked on providing
an “international façades toolbox”
instead of the traditional international
style curtain wall solutions. One of the
key features is the ability to adapt
solutions to different climates, and
thus the toolbox as presented in a
book series published by Knaack’s
Façade Research Group shows a
palette of possibilities of future façade
principles.
The work of the research group is
very much about combining different
disciplines and technologies, in search
of new building “skins”. Some of the
work deliberately try to push the
limits of traditional façade thinking
by using new alternative and even
embryonic technologies. The overall
attitude is that an open mind is
needed to advance the design-related
knowledge and engineering of well-
established researh within this field.
In the discussion the question of
sustainable façade, materials and
recycling came up. As many of the
most promising ideas entails the use
of aluminium, that material was a
natural focal point. Aluminium has got
a bad name due to the current ways
of handling it in terms of recycling,
but according to Ulrich Knaack it still
has the greatest potential.
Finally, some said, all these
discussions about how to develope
sufficient energy saving designs for
old buildings might simply evolve
from the wrong question, even if
the answer did turned out all right.
Sometimes the radical solution in
terms of resources and economics
on the societal level, may be to leave
these preservable brick buildings as
they are, and change the whole
energy production instead.
11

12
The master class participants were divided into three groups, each choosing a focal point
to deal with.

Three Parameters.
In the afternoon session the seminar
divided into three groups. All three
groups were assigned to choose
one key issue, through which they
would approach the challenge of
existing façades. For example the
energy issue, special materials, or
preservation. Would it for example
be possible to keep listed buildings by
wrapping them in some way?
One group dived the question into
an issue of massivity vs. flexibility
in façades. Massive is good,
aesthetically satisfying in for example
brick buildings, robust and easy to
maintain. Flexible is also good, even
necessary, when it comes to energy
saving. But massive and flexible
solutions are hard to come up with.
In developing building materials, it
was argued, there is a tendency to
add an increasing number of different
materials to the structure. As one
participant said, “everytime there is
a new need, we put an extra layer
on, and that is a very old-fashioned
approach, to my mind.” Instead, it
might be worthwhile to consider how
innovation is done within product
design, where they try to use as few
materials as possible, thus developing
in a much more integrated way.
Another participant added that in
the traditional curtain wall façade of
commercial buildings, we would put
tinted glass regardless of which corner
of the earth the façade is facing. In
recent years we have tried to optimize
the building, in terms of orientating
it, twisting it so it is self-shading, and
so on. Thus, although we like the
oldfashioned brickbuildings, they are
perhaps not the most flexible design,
when we think flexibility over the year
or over the day?
In fact, introducing façades with the
same face mask all the way around
is a step back, energy saving-wise.
However, massive walls in composite
materials may have a lot of the
flexible qualities wanted. Hence,
what we might be looking for, was a
another kind of massiveness.
It was suggested to turn the
question around and try and make
massive materials like glass or brick
more open. Walls of foam glass,
for example, could deliver all the
insulation needed and still provide
transparancy. Nowadays it is possible
to produce glass with many different
qualities by adding air or adding
thickness. Thinking in this way, the
window, the insulation area and the
load bearing structure could be found
in the same material or component.
Right now, no big glass block is
available, simply because there is
no market for it.
Other options are gradiant materials
that like a toothbrush shaft goes
from soft to hard, or from porous
to solid in order to support different
functionalities. This was an example
of true flexibility.
It was decided to try and move
forward by bringing down the number
of materials in the façade. To think
in homogenous solutions, why not
use the same material on both the
inside and the outside of the building?
With more and more sophisticated
solutions and more and more layers,
the façade would end up entirely
different from the inner structure.
“Different stages of the same material,
providing different funktionalities
that is what triggers me,” as one
remarked.
In another group they took a
completely different approach. “You
know,” one in the group said, “we are
supposed to come up with more or
less technical solutions. What if we
tried to find out how to move people,
instead of moving technology?” The
metaphor of the challenge was
that of “the new kitchen” as the
focal point for investment in many
private homes, thus overshadowing
any interest in energy saving as part
of refurbishment. But what is it with
that kitchen? It was asked. “Well,”
the answer was, “it gives people this
13

dream of the perfect life; and the new
exterieur wall does not.”
Learning from that, participants
wondered how to change the
behaviour of people in line with the
change the new kitchen prompts.
Thus, how can the envelope frame
the activities of the people and people
frame the envelope? Is it for example,
possible to create a “dialouge
envelope” engaging home owners
like the, partly, aesthetic experience
of the kitchen does? How to expand
the feeling from the kitchen to the
entire building, as it was put.
One main obstacle, it was suggested,
was simply a lack of knowledge.
There is a lot of confusion about
what is to be done even with single
family houses. Among professionals
there might, for example, be a
lot of discussion of passive house
standards. But if one asks people in
the street what that means very few
will know. The average home owner
has very little knowledge of what
kind of effect different measures can
have. What is the impact, how big
is the investment, what is the time
frame on turn of investment? Or was
the knowledge at hand, as another
group member suggested; but the
interest lacking?
The third group brainstormed on the
different drivers in the refurbishment
process, trying to make a matrix of
understanding. As the overriding
theme is energy consumption, it
was for example puzzling that we
keep changing the windows and
then the tenants plug in more and
more energy consuming electrical
gear. How to integrate views and
approaches and make them truly
societal and behavioural?
One of the key points identified to go
into the matrix was that of lifefstyle.
“Why do people want balconies?” it
was asked. “because even if they
live in the city, they want to be in
nature.” All these aspirations have
to be taken into account when we
are trying to understand the drivers
of sustainable refurbishment.
Technical solutions sometimes turn
things around and make us think it
is all about technology, when often
cultural aspects play in. Instead,
the way forward should start out on
the realization that there is no one
solution to the façade question, but
a multitude of approaches. Whatever
the solution, “keep it simple” was
a recurring key phrase of this
discussion.
15

The practitioner’s view.
In the late afternoon talks, entailing
four short “Views on façades,” Simon
Smidt Kristensen from HS Hansen
presented the twigs of frames and
their installation on the façade/roof
on Middelfart Sparekasse, a recently
finalized project. An example of the
on-going increase of industrialization
in building, optimizing the building
process, a key ambition of Hansen
and others is the moving of manpower
and materials from site to production
line. The twigs were installed in just
four days.
Currently, transportation is a
challenge, as the profitability of
many prefab element productions
are ruined by high transport costs. In
the future, however, Smidt Kristensen
envisions elements to be folded and
packed in smart ways, much like
folded satellite disks that are easy
to transport and easy to unfold when
mounted.
Would indeed in the future, non-
professional clients themselves be
able to erect façades like this, it was
asked. The answer is yes, perhaps
a substantial business opportunity
within the do-it-your-self range.
Then, this is an example of embedded
knowledge and skills in new
components and products, which is
essential for the development of user
configurated sustainable solutions.
As especially many privately owned
single family houses are in need of
sustainable renovation, the option
of leaving it to private home-owners
could be an important prospect for
the future.
Marcel Bilow from TU Delft
sketched how the many new
materials in different fields open
up new possibilities for alternative
enveloping. Working with students
at the university they have in Delft
a safer and less expensive testing
ground than on the building site.
Lightweight structures used the
right way enhance functionalities.
Concrete, for instance is already
wellknown, and easy to change by
simple means. Using the principle
of biomimicry, learning from the way
plants are “breathing”, a façade panel
can be constructed of fibre reinforced
concrete with built-in thin, capilary
heating/cooling tubes. Or what
about a wall made up of adjustible
air baloons?
Obstacles to this kind of thinking out
of the box lie primarily within the
conservative construction industry.
Therefore, it is paramount for product
development of ideas like these to
have the industry on board from the
start.
17

Mikkel Kragh from Arup showed
examples of a big market for the
company, namely the tired looking
commercial property that needs a
make-over. This may not be driven
by energy efficiency, and owners
may be more interested in making
it look attractive on the real estate
market. He wanted to emphasize
that envelope design is also about
designing space. And that his
personal view was that flexibility
might not be the most important
goal, and that instead one should
design the perfect and most beautiful
building for a specific purpose, and
then that building would be used and
loved as exactly that.
The groups had two sessions to work on their concepts for the façade of the future.
18
Going through the last decades of
development moving towards a more
advanced façade approach, Mikkel
Kragh stated that architecture is
servicing the structure, and that this
also is implied in the value chain, as
the façade represent a substantial
part of the construction costs. This
is a complex issue and there is no
structured approach to it. It is a grey
zone and very few is taking care of
the building envelope and integrating
the different aspects. All of a sudden
you need to know about industry,
about materials, and all sort of things
in order to be able to design the
building, and not many architectural
practices can afford to have that
knowledge in-house. That is where
the specialists came in 25 yars ago.
Inviting everybody to join the Façade
Engineering Society which he chairs,
Mikkel Kragh showed a building in
London, Ropemakers Place, designed
by Arup, featuring angled windows,
leaning and rotating away from
the sun. Arup was able to predict
the energy saving of their façade
design and that convinced the very
traditionally minded developer to go
with the scheme.
Finally, Tillman Klein from TU Delft
went into the issue of active façades,
and the research into the possibility
of developing concepts for the
combination of façade and building
services.

The second day of the seminar
started with a reminder of the many
barriers the discussion of the previous
day had laid bare, and thus the need
for proceeding in steps to reach the
goals. Tom Hay from Buro Happold
talked about the refurbishment of
social housing using nanogel. Many of
the challenges in such a process turn
out to be different from what might
be expected. Thus Hay reminded the
seminar, how we as professionals
continue to underestimate people’s
concern for things like how many
weeks do they have to move out
during the renovation and so on.
Karsten Bro from Arkitema talked
about his experience of developing
a window panel made of a composite
material with 70 % glassfiber. A
simple and highly efficient system
compared to many products on the
market.
Stig Mikkelsen from Dissing+Weitling
showed examples of how the
architectural language of the
conventional double skin façade can
be transferred to layered façades.
The building for the National Danish
Broadcast, DR-byen, and the new
National Archives, Rigsarkivet, were
cases in point. Emphasizing that a
lot of testing, and the use of a lot
of mock-ups, is essential Mikkelsen
called for a more unitized thinking
both in constructing anew and in
renovation. Finally in that round of
presentations, architect Alexandra
Thygesen talked about “intelligent
façades and intelligent behaviour as
a disregarded ressource”, and the
need for trusting the intelligence of
daily users. The bottom line is thus
that it is better to make the daily
users open the windows, instead of
applying smart mechanisms that use
electricity.
19

The master class participants contributed with animated
discussions and sketches to emphasize their ideas.
20
Conclusion: Comfort, the human
factor, and the simple but clever
brick.
Presenting the findings of the group
session, the group focusing on user
behaviour told the seminar that the
human factor was important for many
reasons. In single family homes,
owners and users are the sole decision
makers and therefore the ones to
initiate change, and single family
homes with a need for sustainable
refurbishment abounds, especially
in Denmark. Secondly, technical
solutions should be developed in
accordance with trends and needs
in a timely fashion. Trying to make
the envelope a tool for change of
behavior, it could in fact be seen as
an educational component of the
building in terms of making people
aware of the need for measures to
be taken.
Thus, it was suggested to publish
a magazine on sustainable
refurbishment with the same
appeal as the popular and attractive
magazines about interior decoration
and design furniture, the “Refurbo
Magazine. This should stimulate
people to use their brains instead of
being passive comsumers, making
it fashionable to do sustainable
refurbishment.
Rather than dealing with these issues
as challenges to the house, the group

suggested to deal with them on a
room level. Or as they put it: “If
you can’t beat the kitchen, join it!”
Thus an idea could be to initiate a
relation between the kitchen and the
façade, bringing the function of the
kitchen to the envelope. Thinking in
interaction between the temperatures
of inside and outside, using rainwater
for the toilet, using the outside as a
refridgerator in winter etc. In this
proposal the envelope acts as the
interface between interior functions
and outside conditions – instead
of protecting ouselves against the
outside.
Group number two had interpreted
the challenge of pushing the envelope
onto refurbishment as “pushing
materials” – rethinking comfort and
increasing the performance of what
is already there, like bricks, instead of
keep adding something. Thinking in
terms of change a few elements over
time and thus increasing the overall
performance retaining the original
design, this group had come up with
what they called the “Refurbrick”. The
idea is to sell a window with extra
benefits. Using the brick would be
ideal for the Danish market, where a
standard size brick totally dominates
in existing buildings.
Taking out the old window and an area
around the window, and putting in a
new one with better functionalities,
reducing thermal bridging around
the frame. A window that extends
into the existing wall reinforcing the
wall. It is insulating but also has a
humidity transport device built into
it. The operation is quite simple as
it is only a partial refurbrickment. It
would indeed be possible to do it
during the sale of the house, when
the seller is out and before the buyer
is moving in.
Mapping the drivers behind
refurbishment, group number three
had listed several, focusing on the
energy aspect. Reducing energy costs
is a crucial driver both for the private
owner and for society, the group
concluded. Then certain parts of
the building could be considered for
special focus, such as the window, the
roof or the envelope. What is needed
is to balance all the options, provide
decision makers with the matrix and
let them act upon it. In this way,
professionals provide the lay person
with a tool, but leave the decision to
him or her. Again, simplicity would
often be the thing to remember. Any
technological fix thus must take its
place in the matrix. Sometimes it is
indeed a question of forcing people
to put on a jumper instead of turning
up the heat. In the concluding debate
one statement stood out and sent
the participants off into the late
afternoon sun: Follow the seasons
– use the raincoat when it is raining.
That is how we should perceive the
functionality and meaning of the
façade.
21

FINALLY THE PARTICIPANTS WERE ASKED
TO GIVE ONE LINE OF ADVICE;
THEY CAME UP WITH THE FOLLOWING
To practioners
Take it seriously
Remember the human factor!
Try partnering with producers, architects, engineers etc
Exchange methodologies and green practices
The best medicine knows the body so well it will cure it by itself,
- passive houses create passiv people
Always recpect the end-user’s needs and preferences
Practicioners should listen to users
To governments
Focus on benchmarks instead of hard numbers
Invest in the key variables
Give incitament; the most important is money e.g. cheap loans
Put the environment back on the agenda after COP 15
Increase transparanecy when choosing options
Governement must create incentives
Governments should listen to researchers
To researchers
Use the advantage of not being in a hurry
Architecture and emotional values are important
Keep it simple
Develop communication tools
Care about the relate to users
Reserarchers should use examples
Researchers should listen practitioners
23

ARTICLES
25

26
FAÇADE REFURBISHMENT
– WHAT IS THE POTENTIAL?
ANNE BAGGER
New buildings, built according to
today’s strict regulations for energy
consumption, only have little impact
on the total consumption of energy
for heating and hot water due to the
proportionally large existing building
stock. Therefore, if old buildings are
either torn down and replaced or
refurbished and brought up to today’s
standard, significant energy savings
may be achieved. Also, interest in
the reuse of building materials and
the conservation of cultural heritage
makes refurbishment attractive.
Fig. 1: Max energy consumption for the heating of
buildings, according to the Danish building standard.
The blue bar to the left is the average consumption for
existing buildings.
Three different scenarios are reflected
upon here. The data is taken from a
publication from the Danish Building
Research Institute (“Potentielle
energibesparelser i det eksisterende
byggeri”, SBi 2009:05). The scenarios
consider the possible energy savings
for heating and hot water in homes
and offices in Denmark, given a
certain extent of refurbishment.
Fig. 2: Some home owners fear that a refurbishment
of their home will end up messy and expensive
Scenario 1:
Buildings with a larger energy
consumption than required by the
1970’s standards are refurbished
and brought up to today’s standards
in terms of insulation. For either
technical or aesthetic reasons only
about 3 out of 4 of these buildings
are considered for refurbishment.
Energy savings: On average 20-25%
of today’s energy consumption for
heating and hot water.
Cost: About DKK 200 billion (25
billion Euros).
Timeframe return on investment:
Investment is earned back in 15-
25 years. (Some of the investment
will be necessary, anyhow, in order
to extend the service life of the
buildings.)
Scenario 2:
All buildings in Denmark are
brought up to today’s standards,
not considering technical difficulties
or aesthetic issues.

(Variant: All buildings in Denmark
are brought to a super-low energy
consumption level)
Energy savings: 35-40% (45-50%)
Cost: About DKK 400 billion (50 billion
Euros) (DKK 560 billion DKR, or 75
billion Euros)
This cost is probably underestimated,
since it does not consider extra costs
for necessary special solutions.
Scenario 3:
Only the poorest insulated buildings
are considered, such as cavity
walls and roofs with a minimum of
insulation. Of these, less than half
are improved, corresponding to
those where there are no structural,
technical or architectural difficulties
involved.
Energy savings: About 5%
Cost: About DKK 30 billion (4 billion
Euros).
The investment is earned back within
5-10 years.
Based on these three scenarios, it
can be concluded that there is a
great potential for energy savings
in building refurbishment. With
the technical solutions available
today, Scenario 2 is not a realistic
possibility. Scenario 1 is possible, and
ideally ought to become reality, but
a number of factors are hindering
this development, leaving scenario
3 as the most likely. Among the
reasons for this are that building
owner’s often are confused about
Fig. 3: All Danish buildings must be assessed and marked by an energy label when it is sold or let out. The energy
label indicates the building’s energy effectiveness, and points out the most obvious improvements to carry out
the actual cost savings, the return
on investment, and how to raise the
appropriate financing, and that they
may worry that the project will turn
out more expensive than estimated.
Also, most private home owners
lack knowledge about the possible
technical solutions, and many people
fear that a refurbishment project will
turn out messy and full of errors.
Among engineers, architects and
craftsmen, there may be a lack of
will and skill to apply new technical
solutions, and manufactures may be
reluctant to vouch for new technical
solutions.
The owners of private homes need
suitable assistance to create an easy
overview of the potential energy
savings, the economy involved and
the technical solutions applicable to
the refurbishment of their home.
Education and certification of
craftsmen, engineers and architects
makes the use of new solutions
easier, and reduces the risk for
the manufacturer. State support
accelerates the use of certain
technical solutions. Public campaigns
may, among other things, focus on
the non-energy benefits of home
refurbishment.
Anne Bagger is a post-doctoral fellow at
the Department of Civil Engineering at the
Technical University of Denmark (DTU).
27

Solid and skeletal construction.
The distinction between solid and
skeletal construction has been one
of the principal ways of categorizing
architecture for centuries.
The construction of a solid material,
whether carved out of existing
structure, like with the cave, or built
from stacked stone or brick, is based on
the structural principle of distributing
loads in a homogeneous structure.
The skeletal construction refers to
the use of timber or steel creating
a structural latticework, to which
membrane components can be
attached. The skeleton takes care of the
structural demands, the membranes
deals with the climatic issues.
After a couple of thousand years
of skeletal wooden construction,
Denmark gradually in the 16th
century, due to lack of wood, turned
its attention to developing solid-
based construction methods based
on masonry. First in the form of
timber framing, but eventually as
full-masonry construction. This
method continued to be refined
by the development of the craft
until it was at such a high level of
perfection, that the material tactility
and the masonry bond itself in the
40ties and 50ties were used as
the primary means of architectural
expression on buildings of otherwise
28
extreme architectural simplicity.
Higher demands, first for speed of
erection, later for higher insulation
values, gradually marginalised the
solid (with insulating cavity) wall. A
version, that still looks like it, but
actually is something completely
different and therefore totally
uninteresting, still exists. In the
meantime the skeletal construction
method, being able to accommodate
for the ever-changing demands of
the energy-related trends, prospered.
By being able to add, remove
or exchange layers of varying
specification, the skeletal frame
structure was the perfect playground
for individual experiments and was
therefore adopted by the architects
as the preferred means of expression.
Refurbishing solids
The result is that solids construction
is seen as a phenomenon of the
past with no actual interest for
modern architecture. An area that
has no future and therefore would
be a dead end to investigate.
The refurbishment of the masonry
architecture, covering almost the
entire city of Copenhagen, except
for a few areas in the western central
parts, suffers gravely under this.
There are no really good solutions
to increasing the energy performance
of this architectural tradition other
THE SOLIDS
JESPER NIELSEN
than covering them with a disguising
and disfiguring (skeletal) coat.
The need for a new solids tradition
One of the major reasons for
the absence of solutions is the
general lack of interest for solid or
homogeneous construction methods.
In order to activate knowledge and
experience in a field, a number of
people must work within that field
and evolve it. Having access to a few,
that remembers “how we used to do
it” is not enough. Only a living and
innovative practice within the field
of homogeneous construction, will
create contemporary solutions. The
evolving practice of digital crafting
makes this even more relevant.
The autarki project
CINARK has embarked in a
number of projects attracting focus
to homogeneous construction
methods. “Textile formwork”, by
PhD student Anne-Mette Manelius,
“revitalization of the masonry
wall” by PhD student Mette Jerl
Jensen and the “Autarki” project.
The Autarki project is not dealing
with bricks, but with cross-
laminated timber. It is focusing on
further development of the present
construction techniques of the
material. Through both technical and
process optimization of the material
use we investigate solutions, which will

improve recyclability and reduce the
energy consumption of the building.
One of the main investigations
concern the ability of the material
to work as a homogeneous (double
shell with cavity) wall, that can
be seen as a continuous surface
from exterior to interior space.
The project will result in a small
experimental building, erected in
1:1 on the grounds of the Royal
Academy School of Architecture in
spring 2011. The building will be
intirely self-sufficient in terms of
energy use and will demonstrate the
architectural and technical potential
in a contemporary solids tradition.
Jesper Nielsen is .Head of Centre at CINARK,
at The Danish Royal Academy’s School of
Architecture.
29

The façade technology of the 20th
century was coined by dissolving
the massive wall, which, in the
search for structural and visual
transparency, led to the development
of the curtain wall. More than sixty
years ago the post-beam-façade
thus became firmly established as a
technical solution. Since then, it has
undergone numerous developments
resulting in a multitude of design
options, as well as high efficiency
in terms of technical performance.
At the end of the 20th century the
main task for building planners was to
combine building design and energy
requirements. Thus research and
design developments focused on the
integration of climate aspects into the
façade technology; the result being
various variants of the double façade:
second-skin façade, box façade,
corridor façade, and shaft-box façade.
Current developments of such
integrated façades, still focused on
energetic improvement, show two
tendencies: the so-called hybrid or
mosaic façade, a combination of a
double façade with a single façade,
to further increase efficiency. And
alternatively, the so-called component
30
Figure 1 – Overview double façades
NEW PERSPECTIVES ON
FAÇADE REFURBISHMENT
ULRICH KNACK
façade; some or almost all building
services components are integrated
into the façade itself, to comply with
the trend toward combining functions
and to increase the performance of
the façade as an industrial product.
The same basic principles of façade
constructions are used for all variants,
aluminum post-beam-system or
element façade, we merely add
additional functions to the existing
system. Along with and partially due to
enhanced legal restrictions they have
undergone improvements in terms of
their thermal properties yet, they still
pose a critical problem for the façade
technology, because on the one hand
a physical contact between the inner
and the outer shell is necessary to
enable load transmission, but on
the other a complete separation
is desirable in terms of building
physics criteria. For the time being,
this seems an unresolvable conflict.
We may still cite Mike Davis, who,
while working for Richard Rogers
on the Lloyds Building in London,
suggested the “polyvalent wall” –
the wall as a monolithic building
component combining the function
of the façade, as well as its
Figure 2 – Double façades, integration of building
services components
controllability and the possibility of
energy generation – a task that both
then and now, 30 years later, cannot
be fully fulfilled. However, this idea
can be viewed as a starting point
for the development of “integrative”,
“intelligent” or “smart” façades.
Today’s developments are – besides
various design trends – primarily
driven by material-related or
technological innovations. the
following topics were identified as
technical corner points of a field of
tension that encompasses the new
developments and the conception of
façades in addition to aesthetic trends:
energy, efficiency and individuality.
Energy understood as the motor for
all actions paired with the actuality
of the energy market; operational
energy and embodied energy in
materials. Efficiency in the sense
of performance expected from the
façade as a technically sophisticated
building component. Individuality
as part of the architecture that
reflects the particular urban, spatial
and aesthetic form of the building.
Figure 3 – Façade Research Group of the Faculty of Architecture /
Delft Technical University

With the increasing awareness of the
need for sustainable solutions, the
relation between façade design and
energy-consumption has become key
to the question of reuse of buildings.
In a market with rising demands
on quality, and on environmental
and financial sustainability, this is
especially relevant for the enormous
number of existing buildings.
The research executed by the Façade
Research Group is therefore based
on a wide range of issues including
building construction, architecture,
installations and finance. This
research has led to the development
of a number of strategies dealing
with the many complex aspects of
office building renovation. Thus, a
strategic overview of the possibilities
and systemized solutions of office
building façades, and a tool box
of various façade refurbishment
instruments for dwellings are being
developed in order to provide for a
decision making process for façade
refurbishment on the international
market, taking architecture, costs,
construction and climate into account.
Simulations have shown that an
energy saving of 75% is possible,
and that there will be a return on
investment well within the lifespan of
the technical components used. Taking
other economic aspects such as the
improvement of material reuse and
the potentials for gained rental surface
and higher rental rates into account,
intelligent renovation seems not only
to enhance sustainability, but also
to make an interesting investment.
The building marked is conservative
– and must be, as building is a
long term investment with many
risks. However, with regards to the
environmental footprint, buildings
should be conceived as having
a long life cycle. But building on
existing knowledge and employing
classic scientific research methods
– problem outline, compilation of
material and knowledge, evaluation
and interpretation, structuring and
lastly the development of subsequent
steps – does lead to rather small
steps in development. On this
background, the Façade Research
Group has employed the idea of
heuristic development in order to
faster identify future developments
and their potential and risks. Thus, in
addition to gaining knowledge about
individual technological options, we
learn to quickly assess and evaluate
them. The analysis does not only
consider purely technical parameters
(construction and energy) as deciding
factors for whether or not a certain
technology is worth pursuing but
also social and economic criteria.
Architects do hate to deal with existing
buildings. They are trained to develop
a story around a location, a function
or a client’s request, and to make this
their own idea in order to differentiate
their design from other architect’s
stories and designs. In dealing
with existing buildings, an existing
architecture must be taken on board,
which means that the beginning of
the story is already set, presumably
even linked to negative or positive
individual or common emotions.
Understanding this, we have to
consider two different main strategies
for the refurbishment of existing
buildings: Either, conservation of
valuable buildings and constructions
with the addition of only the
necessary technical, functional
or aesthetic features. Or, keeping
only the main structure, making
a complete change to a new look,
and using new technology. It is
in this field of tension we have to
position ourselves as researchers,
technologists and designers,
accepting that each building requests
for positions and decisions to be taken.
Ulrich Knaack is Profe sor of Design of
Constructions at the Faculty of Architecture
at the Delft University of Technology.
31

The past year has been dominated
by two issues, which will continue
to impact on the way we go about
our business as building designers.
Firstly, the implications of climate
change and the way our buildings
increasingly need to deliver high
performance and low impact.
The effects are felt in the form of
legislation, but also increasingly
as a demand in the marketplace
for sustainability rated buildings.
Secondly, the economic crisis has had
– and continues to have – significant
implications, and both businesses and
professionals are feeling the strain.
During these difficult times, the
Society of Façade Engineering
(SFE) has been steadily expanding
and raising awareness of the
façade engineering as an essential
component of integrated design and
delivery of buildings and building
envelopes. The discipline is potentially
maximising value for clients and
offering the broad technical approach
needed for the realisation of
sustainable buildings to increasingly
challenging programs and budgets
in a global market. This could be
the decade of the façade engineer.
In his influential work De Architectura,
Roman architect Vitruvius talks about
the three elements of Architecture:
Commodity, Firmness, and Delight.
There are interesting parallels to the
32
THE DECADE OF THE
FAÇADE ENGINEER
MIKKEL KRAGH
nature of façade engineering in that
the building envelope needs to fulfil
the functional requirements and meet
the specified performance criteria,
while having a fundamental impact
on architectural aesthetics and the
intangible qualities of the resulting
enclosed space. This, then, is perhaps
one of the aspects that appeal to a
new generation of technically minded
architects and architecturally minded
engineers? There is no doubt that
the nature of façade engineering can
be both complex and stimulating.
Appropriate application of highly
specialised skills is potentially the
difference between a successful
project and a less successful one
The need for specialist input stems
from the gradual transition from
traditional to non-traditional methods
and technologies. Technological
progress and the industrialisation of
the construction industry mean that
the role of the Architect is changing
from that of controlling the design
through a profound knowledge of
materials and techniques to a role
of orchestration of a multitude of
specialist skills, knowledge, and
industry intelligence – possibly
benefiting from façade engineering
input throughout the various stages
of the design process. The increasing
complexity of the technology and
the recognition that not many
architectural practices can sustain
in-house skills in every field resulted
in façade engineering as a relatively
new professional discipline. The
first façade engineering groups
were set up around 20 years ago in
response to the need for specialist
input on technically challenging
projects. Façade engineering
covers the grey area between the
more traditional disciplines but
also overlaps significantly with
all of them, to varying degrees
depending on the circumstances.
One of the key challenges for the
years to come is the existing building
mass, which needs to be upgraded
to perform to today’s standards and
contribute to the mitigation of climate
change. The building envelope
is instrumental to the successful
combination of upgraded performance
and architectonic qualities. Both
aspects will drive up the value of
Photograph © Christian Richters & Arup Associates

assets and lead to the demand
for new retrofitting technologies
and techniques, including thermal
insulation and solar shading systems.
We need to fundamentally alter the
prevailing perception that existing
buildings are somehow less exciting
than new ones. Requalification of
buildings and cities will become an
increasingly important market and
we need the right technologies and
skills to face the challenges ahead.
The development of advanced
technology has often led to what
appears to be complex buildings with
variable and automated façades that
respond to changes in environmental
conditions and user behaviour. Clearly
these systems represent progress in a
technological sense and, when dealt
with appropriately, the technology
can facilitate high performance and
bring about interesting architectural
opportunities. There is, however,
also a risk that certain systems are
incorporated because they are seen as
advanced technology and have come
to symbolise high performance design
(or even sustainable solutions). ‘Green
Wash’ is the term used to describe
design which is over-sold and under-
delivered as sustainable through
high tech gimmicks as opposed to
Photograph © James Ward & Arup Associates
pragmatic, evidence-based (and
perhaps less exciting) solutions.
Every project is unique and needs to
respond to the client’s requirement,
local climate, etc, and there is no
one-size-fits-all solution for building
design. The aim should always be
high performance - low impact. At
times the appropriate solution will
be a highly technological design, at
other times a passive design will be
more appropriate. Passive design
is based on fundamental principles
and seeks to maximise the benefit of
the natural climate and the physics
of the building form, orientation,
materials, etc. To this end, the
building envelope is of fundamental
importance and much can be gained
from early stage studies of the impact
of the building envelope on the
environmental performance of the
building. Advanced design tools and
appropriate use of building physics has
a lot to offer in this field. In a sense,
we are witnessing a return to design
before the era of air-conditioning
and a rediscovery of fundamental
design principles coupled with
cutting edge technological solutions.
Dr Mi kel Kragh is an A sociate at Arup
where he leads the Façade engin ering team
based in Milan (www.arup.com). Besides
his work at Arup, he is the Chairman of
the Society of Façade Engineering (www.
Façadeengineeringsociety.org); Senior
Visiting Research Fellow at University of Bath;
and Visiting Profe sor at Politecnico di Milano.
33

Building materials differ in many
facets, but when it comes to load
bearing elements for façades the
range seems to narrow down to
just a few, like steel, aluminium,
and wood. In the research done
in the last couple of years at the
Delft University of Technology in the
Netherlands and the Detmold School
for Architecture and Interior Design
in Germany, we have looked into
new material approaches in order
to push the envelope. The following
short descriptions introduce a few of
these experimental constructions, in
which we have tried new materials
and building techniques. Often
the idea behind these concepts is
the integration of functions into
one element. This is a challenging
process, and the insight we gain
from the problems we run into,
will surely lead to new solutions
for the integration of functions.
Development of a heating
panel in fibre reinforced
concrete for a façade
The alternation of the glazing with
floor-to-ceiling unglazed units was the
main aspect of the façade concept.
The idea was that the unglazed
surfaces of the façade should be
used as heating surfaces, to avoid
the traditional solution with a heater
placed in front of the glazed areas.
Façade panels are made up of fibre
reinforced concrete embattled with
34
textile fibres. This constitutes a
load carrying system of the panels,
which can be inserted into the
façade system like standard glazing.
The shell oriented towards the
inside of the building is inlaid with
meadows of capillary tubes that heat
up in the summer and cool off in
the winter. Fibre reinforced concrete
provides a good heat conduction
as well as the sufficient stability,
and is therefore ideal for this use.
Fig: 1
Fibre reinforced concrete
heating panel
GRP-sandwich-construction for
a boat hull in a novel folding
technology
A glass-fibre reinforced plastic (GRP)
boat hull was developed during a
seminar in plastics. This hull was
constructed as a blank and was
built as one even layer as opposed
to usual constructions of boat
hulls. The boat was folded to the
final shape only after laminating
the top layer with rigid foam.
After several tests of the construction,
delamination was ensured to take
place only in the area immediately
of the bend, thus eliminating any
danger of loss of stability. This
small sample was handy for testing
NEW MATERIALS
FOR THE FAÇADE
MARCEL BILOW
during the seminar, obviously more
elaborate tests of the boat hull will
be needed to confirm the stability of
the construction. For use in buildings
it enables the forming of accurate
edges, which can be manufactured
at low cost using a vacuum
moulding press on a workbench
Fig. 2 Folding a boat hull from a flat sandwich panel
Modular Façade in fibre
reinforced concrete
Until now, materials used for extensive
curtain walls have been aluminium,
steel, wood or glass. The development
of fibre reinforced concrete makes
it possible to produce slim profiles
and frames with dimensions close to
those manufactured in aluminium or
steel. The modular façade approach
suggests the possible field of
application of fibre reinforced concrete
and the broadening of existing scopes
for design. The use of fibre reinforced
concrete in façades is commonplace
in panels of curtain walls, whereas its
utilisation for the supporting elements
of the façade is new. The mock-up
model still bears a lot of potential for
development, as it has an elevation

width of only 60mm. The supporting
pillars are filled with rigid foam and
have an average thickness of just 10
mm. The façade unit also includes a
decentral mechanical ventilation unit.
Fig: 3 Façade element of fibre reinforced concrete
Air B Wall
The experimental project Air B Wall
by Jürgen Heinzel, within the scope of
the pneumatic construction seminar
AIR, was developed to be used in
different ways. A huge number of
air filled balloons are embedded in a
clear plastic envelope. Every balloon
can be individually air filled to vary
the sizes of the balloons. If a special
shape is desired, air is outtaken by
the use of vacuum. The deflation
of air from the balloon space will
press the balloons together and
thus establish a stiff load-bearing
element. This principle is well known
from coffee packs, which are solid
hard under vacuum, but soften up
and becomes shapable upon opening.
A possible application is an adjustable
moulding surface enabling low-cost
free-formed surfaces. For indoor
application or for active surfaces
such as media façades, the option
of controlling the shape and pulsation
of each balloon interactively could
be considered. This may also be
applied for temporary use, such as
flexible separation of walls during
façade refurbishment, protecting
office space from the building site.
Fig: 4 Air B Wall
Jackbox – a sandwich wall
approach
The Jackbox Pavilion is an
experimental construction made
to illustrate the use in architecture
of sandwich construction methods
already found in aviation and vehicle
construction. Wall elements are
layered as a sandwich with a GRP
skin, an insulating core, and a fiber
reinforced concrete layer on the
inside. The use of fiber reinforced
concrete allows the addition of
thermal mass, and by additional
insertion of capillary pipes the
wall surface will still be usable as
a wall heating or cooling element.
To enable low-cost manufacturing
of the wall construction modules,
the structure is conceived of as a
planar surface later to be formed
to its final shape. Doors are held
in silicone joints that serve as
connections as well as hinges. The
specially developed tools and aids
for manufacturing this detail, have
been produced with a 3D printer.
Fig: 5 Jackbox Pavillion
Marcel Bilow is research a sociate at
the Façade Research Group at the Delft
University of Technology, and co-founder
of Imagine Envelope.
35

One of the focus points of our research
at the Delft University of Technology
(TU Delft) is façade refurbishment.
The efforts always show one thing:
Successful refurbishment depends
on numerous factors, such as the
financial concept, the architectural
design and others. But it is the
combination of façade and building
services, which is mainly responsible
for the user comfort and the energetic
performance of the building.
This leads directly to the question if
these traditional separated disciplines
should be combined? However
weather the integration of building
services into the façade area is indeed
better than the classical decentralized
concept or not is hard to say. The
comparison is very complex. It has
to deal with indoor climate qualities,
psychological issues such as control
possibilities of the individual user,
space needed for ducting, building
and running costs, maintenance,
warranties and much more.
Figure 1, 2: Schematics of centralized and decentralized building services installations
36
NEXT ACTIVE FAÇADES
- DECENTRALIZED BUILDING SERVICES
FOR FAÇADE REFURBISHMENT
TILLMANN KLEIN
On top of that every building is
different, making a comparison of
executed projects very complicated.
The concept of decentralized
installations is not new, but the
application on modern office
buildings has only recently become
more popular. Not much research
has been carried out in this field.
There is a study carried out by
Institute für Luft- und Kältetechnik
in Dresden, and a recently published
one of the Steinbeiß-Transferzentrum,
based on a two-year monitoring
program of office buildings.
There is indeed an argument that
makes the decentralized approach
interesting for refurbishment: In
order too be independent from the
existing structure, it makes sense
to fit as many installations into
the façade area as possible. The
building envelope can provide all vital
functions and existing installations
can be removed or even left in place.
The goal of the NEXT Active Façades
project we are conducting at TU
Delft is to develop service integrated
façades, based on the product range
of the involved parties. An essential
idea of the concept is to identify
product combinations for the manifold
requirements of a complex market.
The project was initiated as a
joint effort of ALCOA Architectural
Systems, Somfy, TROX/FSL and the
Faculty of Architecture at TU Delft.
Together the parties offer a
broad range of knowledge and all
components necessary for building
services integrated façades. ALCOA
provides unitized curtain walling
façade systems. TROX/FSL offers a
broad range portfolio of decentralized
components, from simple integrated
ventilation units to “all in one”
components for heating, cooling
and heat exchange. Somfy builds
sun-shading systems and control
units and the TU Delft’s role is the

strategic guidance of the project.
The combination of the two
disciplines has different aspects.
First the material interfaces between
components have to be defined. How
will components be attached, where
do pipes and cables run and who is
actually mounting these? How can
the concept be adapted to different
architectural needs? But we also need
to tackle immaterial interfaces: Who
is responsible for the process, the
maintenance and warranty? How
can the product be communicated
to the market and how can decision
makers be approached. The project
shows that the immaterial aspects
are much more difficult to solve than
the more design and engineering
oriented material aspects.
These kinds of integrated products
have to be communicated to
the decision makers at a very
early design stage, because their
introduction has an influence on all
involved disciplines. Therefore we
have developed a calculation tool to
demonstrate the effect on comfort
and energy need of this approach.
At this state of the project, four
different product configurations
have been developed, in order to
be able to react on different market
needs. It starts with simple integrated
ventilation units (for a situation where
the existing exhaust ventilation
system would be used further on)
and ends with a concept where the
new façade provides a functions for
the office space, up to ventilation,
cooling and heating. Basically other
combinations could be realized as well.
A first mock-up has been presented
on the PROVADA 2010 real estate
fair in Amsterdam. The involved
companies are promoting the
concept by using their established
marketing structures (which is
also an advantage of this strategy)
and we can hope to see the first
building with a NEXT façade in 2011.
Tillmann Klein is Head of the Façade Research
Group at the Faculty of Architecture at Delft
University of Technology.
Figure 3:
possible service integration
Figure 4: Mock-up of NEXT faccade on the PROVADA
real estate fair
37

PREFABRICATION AND THE CARE FOR DETAIL
IN REFURBISHING EXISTING FAÇADES
STIG MIKKELSEN
Architecture is very much a
question about the façade. The
façade is the face of the building.
Not only does it communicate to
the world what is happening on
the inside, it constitutes a meaning
and an identity in its own right.
As environmental responsibility
and sustainable energy schemes
become still more decisive drivers in
architectural design, naturally façade
construction should reflect this.
Façades of existing buildings comprise
a particular important aspect, and
rather than replacing the entire
building, more sustainable solutions
ought to be found. But façades are
complex filters between the inside
and the surface of the building,
thus changes to the surface must
be balanced against the provision
of satisfactory indoor climate.
Mainly driven by the advantages of
rational production and installation
methods, over the last decades
production of commercial façades
FACADE REALDANIA 23. september 2010
38
has moved towards prefabrication.
Indeed, also increasing air tightness
requirements and demands for better
insulation values, have played a role in
prompting more efficient production
under more controlled conditions.
Recently, Dissing+Weitling has
completed the new Rambøll Head
Office in Ørestad, Copenhagen. This
project included design of a large,
prefabricated envelope package.
Specifications reflect the increasing
demands on many fields towards
making buildings more energy
efficient, and at the same time
demands for the creation of excellent
work space for years to come.
To ensure that these specifications
were met without compromising the
design in the process of developing
the façade system, many mock-ups
and tests were included in the tender.
At Dissing+Weitling we are convinced
that there is great potential to be
more work off site, thus ensuring
both the quality of the design and
the performance of the Façade.
Our experience with the use of modular
principles and prefabrication in product
design, as well as that of a closer
collaboration with manufacturers,
has led us to believe that also the
refurbishment of existing façades in
some cases could benefit from an
approach based on prefabrication.
However, façade refurbishments, or
”reclads”, often suffer from a severe
loss of architectural quality. Valuable
details are handled improperly,
leading to poor results that violates
the initial design without adding new
qualities to the façade. In order to
refurbish existing façades in a
sustainable and energy efficient way,
and ensure architectural design of a
high standard, both sufficient care,
and the development of new tools
found in doing more testing and based on prefabrication, is needed.
1
Architect MAA Stig Mi kelsen is a partner at
Di sing+Weitling Architectute.

FACADE REALDANIA 23. september 2010
LUFTKVALITET
- MEKANISK VENTILATION
- NATURLIG VENTILATION
TEMPERATUR
- OPVARMNING
- NEDKØLING
AKUSTIK
LYS
- DAGSLYS
- KUNSTLYS
BRAND
- REDNINGSÅBNINGER
- KOLLAPS / SIKKERHED
ENERGI
- DRIFT / VEDVLIGEHOLD
- ØKONOMI
FACADE REALDANIA 23. september 2010
INDSIGT
UDSIGT
INDSIGT
UDSIGT
SOL / VARME
TEMPERATUR
4
Klimaaktive FACADER
DAGSLYS / BLÆNDING
VIND
STØJ / AKUSTIK
39
3

INTELLIGENT BEHAVIOUR
ALEXANDRA THYGESEN
When talking about sustainable
solutions in building design the
development of intelligent façades
often pops up. Generally intelligence
is defined as the ability to understand
and profit from experience. In relation
to façades intelligence is usually
understood as a means of combining
the envelope with regulation of the
indoor climate. In this way the
façade becomes part of the building’s
technical systems for regulating
daylight, lighting, heat, ventilation
etc. Often the regulation is computer
controlled rather than influenced by
the users. Put more provocatively,
intelligent façades are developed
without trusting the intelligence of the
daily users. Is this smart or alienating?
In terms of those intelligent systems
the users are often considered
as disturbing elements due to
their unpredictable behaviour.
Preferably everything is to be
calculated from standards and
norms, which is reasonable in terms
of construction engineering but
does it make sense in relation to
human beings and indoor climate?
Individuals are different and have
varying needs. Sometimes is it nice
to feel the heat of the sun, at other
times it is nice to feel the incoming
air from an open window, but in both
cases only if you yourself decide
when and how. If not it is quickly
transformed into user complaints of
overheating and draft. The sense of
comfort and well being is increased if
people have influence on the indoor
climate but it is difficult to handle
in relation to a standardised mind
set and calculations since behaviour
is an incalculable factor. Is it then
wise just to stick to quantified
standards rather than also focusing
on qualititative requirements and
adaptation to individual needs?
In my opinion an intelligent façade
must be designed within a holistic
architectural framework and by
using, not combating, the climatic
conditions. It does not have to be
complicated. Numerous examples of
multi functional façades can be found
in the history of architecture. Façades
that work, are very durable, have low
costs for running and maintenance
and even are intuitively understood
by the users. It would be unintelligent
not to profit from this knowledge.
The biggest potential for developing
sustainable façades is not necessarily
found in extended use of technical
solutions but in simple utilization of
the climatic conditions combined with
intelligent behavior. It is worth trying.
Alexandra Thygesen is owner of AT Architects
41

42
DANISH SUMMARY
CHRISTIAN BUNDEGAARD
Seminaret ”Pushing the Envelope”
samlede en række førende eksperter
inden for forskning i og produktion
af façader. Eftersom façaden ikke
blot er bygningens ”hud” eller en
dekorativ skal, men en afgørende
del af bygningen både økonomisk,
energimæssigt og funktionelt, er
den et væsentligt indsatsområde for
byggeriets udvikling i de kommende
år.
Det blev da også fuldt ud bekræftet
under seminaret, der som særligt
fokusområde havde bæredygtig
renovering af eksisterende bygninger.
Den eksisterende bygningsmasse
byder på helt særlige façade-
udfordringer, fordi man ud over et
stort behov for at opdatere husene
energimæssigt og funktionelt, ofte
har at gøre med bevaringsværdig
arkitektur, der vil lide ubodelig skade
ved det forkerte indgreb.
De to dages seminar var struktureret
omkring korte oplæg med
efterfølgende diskussion, samt
gruppearbejde omkring udvalgte
aspekter eller problemstillinger.
Oplæggene dækkede et bredt felt
af interesseområder og initiativer:
Energibesparelses-potentialet ved
bæredygtige renoveringer af den
eksisterende bygningsmasse i
Danmark; problemerne med energi-
renovering af murstensbyggeri
med arkitektoniske kvaliteter; nye
materialer og utraditionelle idéer i
udviklingen af fremtidens façader;
bruger-synsvinklen; samt en række
konkrete eksempler på byggerier med
nyudviklede, bæredygtige løsninger
såsom orientering af vinduerne
i forhold til solen, anvendelse af
nano-gel, lette elementer i komposit-
materialer mm.
Diskussionerne i grupper og i plenum
samlede sig om især tre spørgsmål:
Hvorfor er det så vanskeligt at
engagere folk i bæredygtig og
energibesparende renovering? Hvad
skal der til for at skabe innovation og
forandring? Hvordan kan man tænke
funktionalitet, fleksibilitet og design
sammen, så de indgår i en helhed,
frem for at modarbejde hinanden?
Spørgsmålet om øget engagement
og brugerinddragelse blev drøftet
i forhold til den gennemsnitlige
boligejers tilbøjelighed til snarere at
investere i ”det nye køkken” frem
for i en intelligent façade. Hvad var
det med alle disse nye køkkener, og
hvilken lære kunne man uddrage
af denne brugeradfærd med
henblik på udviklingen af attraktive
façadeløsninger?
De mange muligheder for teknologiske
”fix” eller lån af teknologier og
materialer fra andre områder førte
blandt deltagerne til et vist behov
for at trænge ind til princippet bag

teknologi-anvendelsen, frem for at
blive hængende i den rent teknisk-
konstruktive proces. ”Gør det enkelt”;
”tænk på brugeren”; ”tænk på
helheden” lød det fra flere.
Disse holdninger blev afspejlet
i de løsningsforslag grupperne
præsenterede. Én gruppe foreslog
at man kunne gøre façader mere
attraktive for menige brugere ved
at udgive et glittet magasin med det
nyeste i teknisk innovative, smukke
og energirigtige façader – modelleret
over boligmagasinernes indretninger,
møbler og design. En anden gruppe
udarbejdede et forslag til et skema,
der kan kortlægge incitamenter og
barrierer for bæredygtig renovering.
Og den tredje gruppe udviklede et
helt nyt produkt, et nyt ”murstens-
system”, der i forbindelse med
udskiftningen af vinduer ikke blot
erstatter vinduet men også en del
af muren, og som på én gang øger
isoleringsgraden af façaden, sænker
vinduets u-værdi og fjerner fugt fra
murværket, og dermed bidrager til at
forbedre husets indeklima og samlede
energiregnskab.
Den afsluttende debat understregede
behovet for fortsat forskning og
nytænkning, men også for at blive ved
med at tænke i simple helheder, som
at orientere husene rigtigt, anvende
få men effektive materialer, samle
funktioner i få materialer, tænke i
indeklima og ikke mindst i bruger-
synsvinklen. For uden brugernes
interesse og accept når man lige så
lidt, som man gør uden industriens
villighed til eksperimenter.
43

PARTICIPANTS
Alexandra Thygesen, owner, AT Architects
Anja Bache, associate professor, department of civil engineering, Technical University of Denmark
Anne Bagger, post.doc., department of civil engineering, Technical University of Denmark
Anne Beim, professor, the Royal Danish Academy of Fine Arts, School of Architecture
Christian Bundegaard, writer and philosopher
Emanuele Naboni, associate professor, the Royal Danish Academy of Fine Arts, School of Architecture
Hans Kolby Hansen, CEO, Hansen Group
Heidi Pedersen, PR, Christensen & CO Architects
Jesper Nielsen, head of center, CINARK, the Royal Danish Academy of Fine Arts, School of Architecture
Karsten Bro, creative leader, prefab, Arkitema Architects
Lotte Bjerregaard, associate professor, department of civil engineering, Technical University of Denmark
Marcel Bilow, co-founder, Imagine Envelope
Martin Vraa Nielsen, ph.d. student, HLT and the Technical University of Denmark
Mikkel Kragh, associate, Arup
Morten Stender Christensen, m.sc. in engineering
Nanna Gyrithe Jardorf, event coordinator, Danish Architecture Centre
Natalie Mossin, specialist, Danish Architecture Centre
Simon Smidt Kristensen, CEO, HS Hansen
Stig Mikkelsen, partner, Dissing+Weitling architecture
Thomas Bo Jensen, associate professor, the Royal Danish Academy of Fine Arts, School of Architecture
Tillmann Klein, co-founder, Imagine Envelope
Tom Hay, senior engineer, Buro Happold
Torben Dahl, head of institute, the Royal Danish Academy of Fine Arts, School of Architecture
Ulrich Knaack, professor, TU Delft
45

ACKNOWLEDGEMENTS
Initiated and arranged by
Initieret og arrangeret af
Danish Architecture Centre (DAC)
Strandgade 27B
1401 København K
Following on experiences from
I forlængelse af initiativet
Building Lab DK / Byggeriets Innovation
In collaboration with
I samarbejde med
Kgl. Danske Kunstakademi, Arkitektskolen
Royal Danish Academy, Architecture School
Philip de Langesvej
DK-1435 København K, Denmark
Dansk Teknisk Skole (DTU)
DTU Byg, Department of Civil Engineering
Technical University of Denmark
Room 258, building 118, DTU
2800 Kgs. Lyngby, Denmark
Christensen & Co architects
Bragesgade 10b.
DK-2200 København, Denmark
Funded by
Med støtte fra
Realdania
Jarmers Plads 2
DK-1551 København K
47

Pushing the envelope was a two day master
class, taking place at The Royal Danish Academy
of Fine Arts, School of Architecture. Bringing
together specialists and professionals with a
specific interest in façade-engineering from
across business and research institutions.
The purpose of the master class was to facilitate a debate
on the future of existing facades and to develop innovate
ideas to the renewal of the excising building envelope. The
master class examined how we might reap the potential
inherent in renovation - technically as well as architecturally.
This report debates the next steps in the development
of façade solutions for existing buildings.
Published by
Udgivet af
Following on experiences from
I forlængelse af initiativet
In collaboration with
I samarbejde med
Funded by
Med støtte fra