Lisø PhD Dissertation Manuscript - NTNU

Research in Building Physics, Carmeliet, Hens & Vermeir (eds)
© 2003 Swets & Zeitlinger, Lisse, ISBN 90 5809 565 7
Building enclosure performance in a more severe climate
K.R. Lisø, B. Time & T. Kvande
Norwegian Building Research Institute (NBI), Oslo/Trondheim, Norway
E.J. Førland
The Norwegian Meteorological Institute, Oslo, Norway
ABSTRACT: This paper gives an overall view of challenges concerning building enclosure performance in
a potentially more severe climate, based on future climate development scenarios for different parts of Norway.
Preliminary results from the Norwegian Research & Development Programme “Climate 2000 – Building
constructions in a more severe climate” indicates that there is a clear need to further develop our knowledge,
methods, tools and solutions in principal concerning the planning and design of buildings in harsh
climates, in order to ensure a reliable building stock in the future as well. Climate change will entail new conditions
for the Norwegian construction industry. The presented climate change scenarios calls for a systematically
identification of areas in the Norwegian construction industry that are vulnerable to potential impacts of
climate change, and the development of adaptation strategies.
1 INTRODUCTION
Observations increasingly point to global warming
and other changes in the climate system. The Intergovernmental
Panel on Climate Change concludes
that most of the warming observed over the last 50
years is attributable to human activities, and that anthropogenic
climate change will persist for many
centuries (IPCC 2001).
Climatic impact from precipitation, wind, temperature
and exposure to the sun causes extensive
degradation and damage to the built environment
every year. The understanding of how degradation
and damage can best be reduced is of significant importance
in the design and construction of buildings.
Future building materials, structures and external
envelopes will probably have to withstand even
greater climatic impact in parts of Norway than today.
The trend we have seen over the last 10–15
years, with mild autumn-winter seasons with heavy
precipitation and frequent storms along the coast, is
expected to intensify.
Scientists in a wide range of disciplines are exploring
the possible impacts of climate change. Until
now, few studies have focused on the possible impacts
of climate change on the built environment in
Norway. In other countries impact studies have been
performed along with studies of climate development
under global warming. A British study (Graves
& Phillipson 2000) shows that an increase in wind
speeds of 6% is likely to cause damage to 1 million
buildings at a cost of £1-2 billion. The study also
addressed the major impacts of increased driving
rain quantities on the suitability of different types of
building enclosures, and the likely increase of maintenance
costs due to more extreme weather in parts
of England. Dry summers in the south of England
could cause a 50–100% increase in subsidence
claims in vulnerable areas.
A study published by the Building Research Association
of New Zealand presents climate change
impacts on building performance in New Zealand
(Camilleri et al. 2001). The study concludes that future
performance of buildings in New Zealand may
be significantly different from the current performance
with regard to coastal and inland flooding,
overheating, and wind damage and flooding associated
with tropical cyclones.
2 RESEARCH BACKGROUND
2.1 Extreme weather events of the last ten years
Coastal communities in Norway are vulnerable to
strong winds. The hurricane that occurred in Northwest
Norway on New Year’s Day 1992 caused damage
to buildings in the range of 166 million Euro.
Wind speeds of 62 - 63 m/s were recorded, the highest
wind speeds that have ever been recorded on
mainland Norway. The bulk of the damage was incurred
to roofs and roofing, due primarily to insufficient
anchoring.