Improving Australian Housing Envelope Integrity – A Net Benefit Case for Post Construction Fan Pressurization Testing

Improving Australian Housing Envelope Integrity – A Net Benefit Case for Post Construction Fan Pressurization Testing

Authors:

Jesse Clarke

Organisation of Presenter:

CSR, Australia

Abstract:

The case is presented for performance based sealing and verification of as-constructed air leakage rates in new housing in accordance with AS/NZS ISO 9972. Based on 2015 housing approval data the report concludes air sealing verification is greatly beneficial to Australia and is valid for inclusion in the 2019 Building Code.

Recent research by CSIRO has shown that the current prescriptive methods outlined in the BCA for sealing construction systems are not effectively achieving their purpose in 65% of cases and not fulfilling the NCC objectives to reduce carbon emissions. This also has potential sub-optimal outcomes for health, amenity and fire safety.

The analysis shows that the energy provisions can be greatly undermined by high air leakage rates through the building envelope. An achievable and realistic building code performance benchmark enabling post construction testing using AS/NS ISO 9972 will deliver an economic BCR of 1.7 @ 7% discount rate for 25 year projections and as high as 2.5 @ 3.5% (IPCC) discount rate meaning that air sealing verification in new housing is both economically and environmentally responsible. Australia may enjoy $255 – 371 million of economic benefit gained by $146.7 Million per year investment in air sealing technologies and practices.