Lisø PhD Dissertation Manuscript - NTNU

Lisø, K.R./ Building envelope performance in harsh climates: Methods for geographically dependent design
Part C presents methods for geographically dependent design of building envelopes.
A method for assessing the relative potential of frost decay or frost damage of
mineral materials exposed to a given climate is expressed in Paper IX. A national
map of the potential for decay in wood structures in Norway is presented in Paper X.
Detailed scenarios for climate change for selected locations in Norway are used to
provide an indication of the possible future development of decay rates. A method
for assessing driving rain exposures based on multi-year records of synoptic
observations of present weather, wind speed and direction is presented in Paper XI.
These and other indices, with established quantified relations between climatic
impact and material behaviour or building performance, can be used as a tool for
evaluation of changes in performance requirements or decay rates due to climate
change under global warming incorporating data from regional- and local-level
climate change scenarios as indicated in Paper X. Historical records of climate data
have also been used to illuminate challenges arising when introducing international
standards at the national level, without considering the need for adjustments to reflect
local climatic conditions. The appropriateness of the exposure coefficient given in
the design standard on roof snow loads now in force is analysed (Paper XII),
illustrating the importance of scale in standardisation. Norway has areas with both
high snow loads and high frequencies of wind. It is shown that the exposure
coefficient does not reflect the actual effects of wind exposure on roof snow loads in
these areas.
An overview of main findings is presented in the following sections, referring to the
twelve individual papers constituting this dissertation. Detailed presentations of
results are given in the individual papers.
2.2 Methodology overview
The following research methods have been applied to obtain the presented results:
Analyses of climate change scenarios (Paper I, Paper II and Paper X).
Overall analyses of data from the Ground Property, Address and Building
Register (GAB register) as a basis for a vintage model of the robustness of
the Norwegian building stock (Paper III and Paper VIII).
Analyses of risk assessment methods (Paper IV).
Analyses of building defect assignment reports in the SINTEF Building and
Infrastructure’s Building defects archive (Paper V).
Case studies of building defect assignment reports related to weatherprotective
flashings and masonry structures (Paper VI and Paper VII).
Field investigations of snow loads and wind actions on buildings (Paper
VIII).
Analyses of climate data from the Norwegian Meteorological Institute’s
Climate archive (Papers IX-XII).
Literature surveys (all papers).
Methods and delimitations are thoroughly described in the referred individual papers.
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