Lisø PhD Dissertation Manuscript - NTNU

Learning from experience – an analysis of process induced building
defects in Norway
K.R. Lisø & T. Kvande
SINTEF Building and Infrastructure/ Department of Civil and Transport Engineering, Norwegian University
of Science and Technology (NTNU), Oslo/Trondheim, Norway
J.V. Thue
Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU),
Trondheim, Norway
ABSTRACT: This paper presents a comprehensive review of process induced building defects investigated by
SINTEF Building and Infrastructure in the 10-year period 1993-2002 (2,423 cases registered and described in
2,003 assignment reports). Defects related to the building envelope constitute 66% of the investigated cases. A
bulk of the defects (76%) is related to moisture, and many types of building defects are recurring items, indicating
a general lack of knowledge concerning fundamental principles of building physics. A wide range of
classical problems is recorded, e.g. unfortunate design and use of materials, inaccurate craftsmanship, structure
and composition of rendering layers and paint on porous, mineral building materials, inappropriate rendering
layers on facade systems with rendering directly on thermal insulation, and insufficient efforts to protect
against moisture in general. These findings support earlier investigations concluding that the construction
industry is not able to learn from past experience and that the exchange of knowledge is not satisfactory.
1 INTRODUCTION
1.1 Principal objectives and scope
SINTEF Building and Infrastructure’s archive of
building defect assignments represents one of Norway’s
most important sources of knowledge on types
of process induced building defects and related
causes. This knowledge is now being thoroughly
analysed. Preliminary registration work has been reported
through work carried out by master students
at NTNU (Sagen 2004, Bjerkevoll 2004, Bjerkevoll
2005) and some overall results were presented by
Lisø et al. (2005a).
Ingvaldsen (2001) defines “process induced
building defects” as absence or reduction of presupposed
capacity that is discovered after a construction
project has been completed and taken over by the
owner, and which he demands to be repaired. Thus,
process induced building defects bring about exceptional
maintenance costs, i.e. cost that should not
have incurred – or additional costs related to a more
frequent maintenance than forecasted. All because
the actors involved have not succeeded in fulfilling
requirements in standardised or generally recognised
methods or specifications. Defects caused by normal
wear and tear are not defined as building defects.
The principal objective of the presented investigation
has been to establish an electronic process induced
building defects archive, adopting the definition
above and based on building defect assignments
carried out by the institute in the period 1964 until
today. The work form a central part of a PhD study
within the SINTEF Building and Infrastructure’s research
& development programme “Climate 2000”
(Lisø et al. 2005b). The main objective of establishing
such an archive is to allow for the preparation of
a review of the Norwegian building stock and building
practice in order to evaluate how different types
of buildings and structures could be vulnerable to
possible impacts of climate change due to global
warming. The results will also be used in the further
development of best-practice solutions and highperformance
building envelopes in different climate
zones.
There are obviously also other areas of application
for this considerable source of experience-based
knowledge. The results will finally be used as a basis
for the development of more accurate criteria and
Codes of Practice regarding the design and functionality
of critical elements of buildings, and incorporated
in the appropriate SINTEF Building Research
Design Sheets.
This paper present results from an investigation
of all process induced building defect assignments
carried out by the institute in the 10-year period
1993-2002 (2,003 reports describing 2,423 incidents
or cases of defects), together with a thorough description
of the methodology applied. These assignments
represent valuable examples for future learning.