Scoping study of condensation in residential buildings - Final report

This scoping report was instigated by the Australian Building Codes Board (ABCB) in response to concern raised by building regulation stakeholders that new Class 1 and Class 2 buildings were experiencing unacceptable levels of condensation and mould. The persistent presence of condensation in buildings is linked to negative impacts on human health and amenity, as well as building structural integrity. Many factors within the design, construction and building occupation can contribute to the presents of condensation. However, in Australia, recent changes in the type and complexities of the modern built fabric and increased consumer expectations of thermal comfort within Class 1 and Class 2 buildings may have led to the establishment of building typologies that may not always be suitably equipped to manage vapour pressure, condensation and mould. Since, condensation within buildings is a complex and inter-related phenomenon, any successful mitigation strategy must take a holistic approach to the problem.

This Scoping Report sought to identify the key issues that may contribute to condensation in Australian Class 1 and Class 2 buildings. Specific focus was given to any factors arising from building regulation within the legislative framework, which requires the ABCB to develop regulations within Volume One and Volume Two of the National Construction Code (NCC) which provide Safe and Healthy environments for building occupants. However, the NCC also relies on the quality of many referenced Australian Standards and technical documents. Within this context, the ABCB may be required to liaise and apply regulatory pressure on Australian Standards committees to improve relevant documents. Similarly, as the ABCB establishes national minimum requirements, it may need to provide assistance and guidance to industry stakeholders, State and Local Government and consumers.