The Green Building Council of Australia (GBCA) has commended the recent updates to the National Construction Code (NCC) noting the significant improvements in energy efficiency across the country.

Over 75% of new homes in NSW are now rated above seven stars, highlighting the positive impact of these new standards.

GBCA chief executive Davina Rooney says these costs were anticipated when the standards were updated and will be offset by homeowners through energy bill savings of $326 per year, thanks to the improved energy efficiency of their homes.

“The long-term savings make the transition to higher energy efficiency standards a win-win for everyone. The improved energy efficiency of these homes is expected to reduce carbon emissions by 18 to 28%, making this investment beneficial for both the planet and the household budget,” Davina says.

“These upfront costs are a smart investment. Homeowners will not only see reduced energy bills but also enjoy more comfortable living environments.”

CSIRO analysis of industry changes following the code update shows that in NSW the amount of double glazing used in apartments has remained consistent with levels seen before the changes.

Developers have managed costs by slightly reducing the size of windows, which means there hasn’t been a significant shift in the types of products used, leading to only a small change in costs.

In NSW, however, where 80% of new homes now exceed the seven-star rating, the average home size has grown over 10% and window areas have increased by 10m².

This has led to a rise in double glazing usage, now covering 27% of average window areas, contributing to the higher costs. However, the energy savings and improved comfort levels are seen as a worthy trade-off.

By contrast, in Queensland, where the average home size has remained stable and window areas have slightly decreased, the cost increase has been much lower. The smaller window sizes in Queensland homes have meant that double glazing was often not required, resulting in more modest cost increases.

These findings illustrate the diverse approaches states are taking to meet the new NCC standards with Queensland setting a strong example of how maintaining existing home sizes and optimising window design can achieve cost-effective compliance with the updated energy efficiency requirements.

The National Construction Code (NCC) 2022 energy efficiency updates, including the transition to the NatHERS seven-star standard, have currently been implemented in NSW, Victoria, ACT and Queensland.