Australian building codes and criteria fail to adequately address a major source of widespread energy inefficiencies in the country’s built environments, namely air leakages in the building envelope that raise the difficulty of maintaining steady indoor temperatures.
A guide produced by the Australia’s government on sustainable housing estimates that air leakages comprise around 15 to 25 per cent of heat loss during the winter months in Australian homes while also impeding cooling effects across the summer.
While the government recognizes the negative impact of air leakages on the energy efficiency of homes, Australia still severely lags other jurisdictions in the Anglosphere when it comes to introducing testing and criteria for the air tightness of buildings.
The UK has made the testing of many buildings for air leakages mandatory via Section L of its Building Regulations, while in the US an increasing number of states are instituting similar requirements for residential buildings, following the example set by the International Energy Conservation Code.
The New York State Codes Committee, for example, is currently considering the adoption of testing requirements for the air tightness of building envelopes as well as the ductwork of residential buildings, as contained by the 2015 iteration of the International Energy Conservation Code.
As early as the mid-1990s, initial versions of America’s voluntary ENERGY STAR for Homes program contained testing requirements for air tightness. Version 2.0 introduced sealing requirements in 2006, while by 2011, Version 3.0 ratcheted up the criteria for air tightness.
In stark contrast to the UK and US, Australia’s National Construction Code does not even make reference to the testing or inspection of building air tightness, despite advocating draught sealing in its Section J.
While the Building Code of Australia has made a move in the right direction with calls for the mandatory testing of certain large-scale ductwork systems, Australia’s construction industry still has a long way to go if it wants to catch up with the US and UK, where leakages have already been a focal point of efficiency discussions for decades.