Condensation in Buildings - Australian Building Codes Board

Information Handbook: Condensation in Buildings
1 Introduction
Reminder:
This Handbook is not mandatory or regulatory in nature and compliance with it will not
necessarily discharge a user's legal obligations. The Handbook should only be read and used
subject to, and in conjunction with, the general disclaimer at page ii.
The Handbook also needs to be read in conjunction with the building legislation of the relevant
State or Territory. It is written in generic terms and it is not intended that the content of the
Handbook counteract or conflict with the legislative requirements, any references in legal
documents, any handbooks issued by the Administration or any directives by the Building
Control Authority.
1.1 Background
The Condensation in Buildings Information Handbook is a revised second edition of a document
prepared by the Australian Institute of Architects (AIA) and published by the ABCB in 2011. The
first edition noted that it was “intended to assist architects, designers and builders in the
assessment of the risk of condensation and its consequences”. The 2011 Handbook has
attracted considerable attention on the ABCB’s web site, suggesting that interest in these
matters extends beyond the community of building practitioners who work with the regulatory
provisions of the NCC.
The second edition consolidates information from the first into a more extensively illustrated
form in the hope of improving the Handbook’s accessibility and usefulness to a wider audience.
It also draws on the insights and recommendations of researchers and practitioners, in Australia
and overseas, who continue to explore the complexities of a still developing body of knowledge
and report informatively on their understanding and experiences.
The state of flux is acknowledged in ASHRAE Standard 160-2009. This standard, which is
outlined in Chapter 6, provides a consensus view from the American Society of Heating,
Refrigerating and Air-Conditioning Engineers (ASHRAE) on suitable inputs to advance methods
of simulating condensation risk. The Foreword notes that “many items in this standard are
based on incomplete information and are, therefore, partially based on the best professional
judgment of the standard committee at the time of writing. The development of this standard has
pointed to many unanswered questions, questions that hopefully will be addressed and
answered by research in the near future.”
DRAFT HANDBOOK
While work progresses on unanswered questions, the climate is also in flux. Many buildings
designed today will serve in an environment where extreme weather events are predicted to be
more frequent and climatic patterns may shift to create unfamiliar combinations of precipitation,
humidity and seasonal temperatures. These circumstances suggest that condensation
management strategies based only on established expectations, rules of thumb or narrow
margins of safety are unlikely to stand the test of coming decades.
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