According to a draught update submitted for public comment, the most substantial update to the National Construction Code in more than a decade will raise the required thermal performance of homes from the present level of 6-stars NatHERS to the equivalent of 7 stars.

Every three years, the National Construction Code (NCC) is modified based on industry research, public feedback, and government policy directives.

In order to satisfy promises made under the Paris Agreement to reduce glasshouse gas emissions, the federal and state construction ministers asked the Australian Building Codes Board to draught enhanced domestic energy efficiency standards.

As well as the stringency increase to 7-stars, the proposed changes introduce a “whole-of-home approach,” with an annual energy use budget for the regulated equipment in the home, such as air conditioning, heated water, lighting, swimming pool and spa pumps.

This method allows for equipment efficiency to be traded in order to meet the annual energy use budget. On-site renewables can be used to offset the energy consumption of the equipment, but not the fabric of the building.

Trivess Moore, a senior lecturer at RMIT University's Sustainable Building Innovation Lab, responded to the planned modifications by saying that the expected increase from 6 to 7 stars was a key step towards "near zero carbon/energy housing."

“An increase from 6 to 7 stars would result in an average reduction in energy for heating and cooling of 24 percent across Australia,” he said.

“The performance of new Australian housing is at least 40 percent worse than many other developed countries in similar climate zones. While the move to 7 star will close this gap, there is much more that we could be doing right now.”

“Research undertaken at RMIT University found that more than 80 percent of new housing in Australia is only built to the minimum 6 star standard, with less than 1.5 percent built to the optimal environmental and economic performance of 7.5 stars demonstrating the need to improve minimum regulatory requirements."

“Increasing the minimum star rating alone will not be enough. There is an issue across the industry with performance not matching design outcomes. Any changes to minimum performance requirements must be accompanied by greater accountability in the building industry to deliver improved outcomes.”

The suggested amendments are being discussed by the Australian Building Codes Board in two stages. The first stage ran from May 10 to July 11, 2021, while the second is open until October 17. This third stage of consultation seeks feedback on the technical provisions for energy efficiency and condensation.