As building ministers consider a modest step up to minimum energy efficiency standards in Australia’s National Construction Code, some builders and developers are already delivering better homes.
It’s been more than a decade since the current 6-star minimum NatHERS rating was introduced into the Building Code of Australia. Since then, pressure to step up to 7 stars has been steadily growing.
Following years of sustained advocacy from industry groups, notably the Property Council and Australian Sustainable Built Environment Council, a draft of the 2022 National Construction Code was released in August.
The Property Council’s position is clear: “Industry is far better off if we have a known forward trajectory of modest adjustments to building codes rather than infrequent, large lurches,” says Property Council chief executive Ken Morrison.
Small increases to energy efficiency standards can deliver big dividends. Built to Perform, a report published by ClimateWorks and ASBEC in 2018, found that a 7-star minimum would save $2 billion in household energy bills by 2030, as well as nine million tonnes of carbon emissions.
A more recent report by Renew, published in August, found elevating energy efficiency standards would lower emissions, put more money in residents’ pockets and help home owners pay off their mortgages faster.
Small, subtle shifts
As building ministers deliberate, some builders have been getting ahead of the likely changes. The Victorian Government’s 7 Star Homes Program, delivered by Sustainability Victoria, is helping 29 builders and land developers accelerate the transition to 7-star homes, and among these are some of Australia’s largest volume builders.
Claire Ferres Miles, Sustainability Victoria’s chief executive officer, says the program has attracted interest from small and large builders, and this “is testament to the industry-wide shift that we’re seeing toward more energy-efficient and sustainable homes”.
Creation Homes is one of the builders signed up to the 7 Star Homes program. Creation Homes’ Apollo, a net zero, 7-star NatHERS home at Stockland’s Orion estate in Melbourne’s Braybrook, was delivered in 2020. Modelling has found the improved NatHERS rating, together with efficient appliances and rooftop solar, mean the home is 50 per cent cheaper to run. It also saves homeowners around $1,000 on energy costs each year, and entirely eliminates emissions from energy use.
“Before we started the Apollo, we found the idea of 7-star NatHERS quite daunting,” says Creation Homes’ operations manager, Charbel Safi. “But in hindsight, it wasn’t much harder to achieve than 6-star NatHERS. It just required small, subtle shifts.”
To achieve the airtightness requirements, extra caulking, sealing and thermal testing were completed. Upgraded glazing came at an extra cost, but Safi notes that “the upgrade in glazing significantly increases the star rating of the home, in most occasions to 6.4-6.5 stars”. He has been in talks with materials suppliers in recent weeks who are increasingly prepared to “bridge the gap” to drive down costs, he adds.
“We will continue to expand our footprint in this space with our upcoming 8-star builds for Metro’s Northcote Place development, comprising 74 townhouses with an average NatHERs rating of 8 stars,” Safi says.
From prototype to standard pattern
Stockland is principal partner of the Green Building Council of Australia's Future Homes program. The GBCA launched a new Green Star Homes standard in 2021 to certify healthy, resilient and climate positive homes equivalent to 7 or 7.5 star NatHERS.
Penny Austin, Stockland’s sustainability manager for communities, says 7-star rated homes are no longer prototypes and are becoming increasingly mainstream as homeowners become more environmentally-conscious and seek ways to reduce their cost of living.
“Last year, almost a quarter of our medium density homes nationally were delivered to 7 stars or above, and in a first for Australia, our pilot home at Stockland Waterlea in Melbourne has just been certified by the Green Star Homes standard,” Austin says.
Similarly, every home at Mirvac’s new masterplanned community, The Fabric in Melbourne’s Altona North, will achieve a minimum 7-star rating, says Mirvac residential general manager in Victoria, Elysa Anderson.
Mirvac is also trialling net zero energy homes at The Fabric, with ARENA providing $784,000 to deliver 49 fully-electric, 7-star town homes in stage one. “We have a long-term goal to improve our residents’ lifestyles by reducing their energy bills and environmental impact,” Anderson says.
The minimum 7-star rating has been achieved using a combination of strategies, including solar orientation, thermally-broken glazing and additional under-slab and roof insulation. Fully-electric, energy efficient appliances and rooftop solar are included with battery storage as an upgrade option.
The first residents will move into their new homes from early to mid-2022, and Anderson says The Fabric’s minimum 7-star rating has been “a key to the project’s success”.
“Fully electric homes are no longer a barrier to sale and we are seeing high levels of sustainability upgrades from purchasers keen to help reduce their energy bills and carbon footprint,” Anderson adds.
7-star as standard
Sustainability Victoria’s Claire Ferres Miles is optimistic about the future.
“Through the 7 Star Homes program, Victorian builders are stepping up to drive the transition to a circular and climate resilient clean economy,” she notes.
“With each build, these builders are proving that energy-efficient homes can be designed and constructed using many of the same materials and technologies currently used today, at an affordable price.”
Creation Homes’ Safi is also upbeat.
“If we all look at this together – volume builders, suppliers and big developers – we can move quickly to 7-star as standard. I think it won’t be long at all before 7-star is specified with little cost difference.”