The expansion of the Nationwide House Energy Rating Scheme (NatHERS) to include existing homes has hit the mainstream media with fanfare and high hopes that it will help home buyers and renters understand what their energy bills will be and logically drive their decision-making around this.
The principle behind the NatHERS expansion is to replicate the enormously successful NABERS rating system that obliges owners to disclose the energy efficiency of commercial buildings, and that is credited with making Australia a global leader in energy efficiency.
The logic is the industry adage “you can’t manage what you don’t measure.”
The new stage of the rollout to an expanded target group of homes follows a trial period for the scheme previously available only for new homes through their design, materials and construction, fixed appliances and on-site energy generation and storage for the last three decades.
The alternative rating system, Scorecard, will wind down.
The federal government flagged a $32.7 million investment into expanding the NatHERS scheme at the end of last year in its 2025-25 Mid Year Economic and Fiscal Outlook.
It was part of a range of initiatives included in its $8.3 billion investment over 15 years to support the Net Zero Plan to meet Australia’s 2035 emission reduction targets, which, on the advice of the Climate Change Authority, the government has declared it to be 62 to 70 per cent from 2005 levels last year.
The Climate Change and Energy Assistant Minister, Josh Wilson, said the funding will allow the expansion of the scheme to be available from mid-2026 onwards. He described the scheme as “just like energy star ratings for household appliances” and will help renters and homebuyers access upfront information about energy efficiency and costs to help them make decisions about upgrades.
Wilson said around 70 per cent of Australia’s 11 million existing homes were built before the introduction of minimum energy efficiency standards, meaning results were likely to be below three stars, when 7 stars is the nationally mandated minimum. Even improving a home from 3 to 5 stars would reduce the energy needed for heating and cooling by 40 per cent, as well as reduce cost and emissions, he said.
“This funding will enable more Australians to make informed choices about their homes in order to realise savings on their energy bills and enjoy more comfortable homes in a changing climate.”
The July launch of the expanded NatHERS program will target an expanded group of homes from last year’s trial.
Hidden in the details was a note saying moving from doing “desktop assessments” to “dealing directly with households” will result in “higher administrative costs” until there is “a fully fledged disclosure market, possibly supported by cost recovery”.
Selected households will receive a home energy rating certificate from a NatHERS assessor, which will include practical information on the most cost-effective upgrades available for the home.
Design Matters National was recently named the exclusive accreditor for NatHERS assessors and will begin assessing applications from April 2026.
According to the NatHERS website, the scheme is currently “scaling up” to meet the demands of stage 2, which would include refining processes, tool and communications, as well as training up and accrediting assessors. Also included in this period is a pilot run of the Home Energy Ratings Disclosure Framework in NSW, which will inform further refinement of the scheme prior to the rollout.
Stage 2 will feature upgraded tools, assessment methods and processes, open up accreditation and provide more opportunities for households to get an assessment – although exactly how remains unclear.
In updates this month, the energy ministers indicated they had “agreed [on] the model for delivery” and that it will “reduce administrative complexity and manage risk.”
They also said the agreed model was based on feedback from a consultation in August 2024, where more than 40 submissions were received from assessors, community and industry groups, including webinars, attended by about 750 people.
However, documents around this decision don’t answer the burning question: where in the world do I sign up? There are a few hints.
NatHERS notes that there will be a single energy rating calculation tool available: CSIRO’s AccuRate Enterprise existing homes model, which will “calculate ratings and generate certificates.”
The model “differs from the current NatHERS delivery model”, and the expansion will support “a more active role of the NatHERS Administrator”, the document said.
“While NatHERS for new homes is essentially industry self-regulated and funded, the existing homes model proposes greater administrative controls, providing more certainty for delivering tools to the market and allowing for action to be taken on assessors to address issues as they arise.”
Hidden in the details was a note saying moving from doing “desktop assessments” to “dealing directly with households” will result in “higher administrative costs” until there is “a fully fledged disclosure market, possibly supported by cost recovery”.
It also looks like there is a suggestion that households will need to apply directly to NatHERS for an assessment.
And now what happens to Scorecard?
When The Fifth Estate first ran the story about the NatHERS trial, our phones blew up from Victorians upset about the lack of mention of the Residential Efficiency Scorecard program – the state’s own energy rating tool that has been developed over 10 years.
At the time, the tool had served more than 11,000 home occupants through just 150 assessors at the cost of a couple of hundred dollars per house. One assessor said the NatHERS existing homes tool “required data that was far more complex to gather.”
The government has announced that Scorecard will officially close on 23 June 2026, saying it will be winding down the delivery of training, accreditation, quality control and tool operation through the first half of 2026. Although Scorecard assessments will still be available for those who want them.
The website said that while Scorecard had been a “successful first step” since 2017, the “NatHERS expansion is the next step”.
“NatHERS for existing homes has been shaped by Scorecard experiences and is being enhanced based on feedback from trial assessors, households, stakeholders and governments.”
Wilson said:
“The National Climate Risk Assessment clearly shows that hazards such as heatwaves will continue to intensify in the coming decades. Taking practical steps to improve energy performance in our homes will be critical to support Australians in their efforts to adapt to the impacts from climate change.
“This announcement forms part of a wider package under the Albanese Government’s Built Environment Sector plan to reduce the energy we use, lower costs for households, cut emissions, and create more liveable, resilient spaces.”
Go for practical power use.