The Australian Building Codes Board (ABCB) released draft National Construction Code (NCC) provisions on energy efficient residential buildings for public consultation until 17 October, 2021.

The Australian Sustainable Built Environment Council (ASBEC) welcomed the release of the public consultation draft as an important step change towards more healthy and comfortable homes for Australian families.

Minimum energy efficiency standards for housing haven’t shifted substantially for over a decade. The proposed update is to ensure the National Construction Code meets the targets set out in the federal government’s Trajectory for Low Energy Buildings.

ASBEC president, Ken Maher, said more energy efficient houses provide a win-win opportunity in terms of jobs, energy savings and emission reduction and are essential for a zero carbon future.

 “Australia’s homeowners and tenants need certainty that they are gaining the health, comfort, efficiency and environmental benefits that they could reasonably expect,” he said.

Chair of ASBEC’s building quality taskforce, Tony Arnel, said more energy efficient buildings offer more resilience to extreme weather, better comfort and reduce stress on the electricity grid.

“At a time when bill savings and consumer empowerment are more important than ever, we welcome the Australian Building Codes Board’s actions to facilitate improved home energy for NCC 2022,” he said.

The research in ASBEC’s publication, Built to Perform, shows that delaying cost-effective changes to the Code by just three years (for example, implementing changes in the 2025 Code instead of 2022) could cost $2 billion in household energy bills between now and 2030.

The delay would also lock in nine million tonnes of emissions to 2030 and 22 million tonnes to 2050.

ASBEC’s interim executive director, Alison Scotland, said buildings offer one of the most cost-effective, jobs-rich opportunities for energy savings and emissions abatement, with broader benefits that cannot be ignored.

She said the government’s commitment to energy productivity for households is the right priority right now and there is a big opportunity to do much more in coming years.

The NCC proposal is the most significant revision to the residential construction code since the introduction of 6 star ratings in 2010, according to Dr Trivess Moore, senior lecturer at RMIT University’s Sustainable Building Innovation Lab.

“The likely increase from 6 to 7 stars as a minimum performance requirement is a critical step on the path towards near zero carbon/energy housing,” he said.

“An increase from 6 to 7 stars would result in an average reduction in energy for heating and cooling of 24 per cent across Australia.

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

Moore said research undertaken at RMIT University found that more than 80 per cent of new housing in Australia is only built to the minimum 6 star standard, with less than 1.5 per cent 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,” Moore said.

Senior Industry Fellow at RMIT University, Alan Pears, said Australia’s progress on building energy performance has been overly dependent on regulation as the main driver for the past 30 years.

“Regulation only sets basic minimum standards and provides no reward for innovators and leaders. Regulation is slow to respond to the rapid changes we are facing,” Pears said.

“COVID is driving greater focus on the tensions between indoor air quality, high ventilation rates and energy efficiency. These can be resolved by energy recovery ventilation, which preheats or precools incoming air using exhaust air, or by high efficiency air purifiers.

“The 2019 NCC introduced separate requirements for summer and winter, which was a step forward. 2022 will see updated climate data, but not data reflective of conditions that will exist over the life of a new dwelling,” he said.

“We need much more focus on summer performance. This should include performance in late summer and autumn, when the sun is lower in the sky but extreme heat will be more likely. This will require more focus on adjustable shading.

“New home buyers deserve better information to guide their decisions. For example, existing rating tools can show how each room performs in extreme hot and cold weather. Regulations should require that this information be provided before a buyer signs up."