Existing homes

The Australian Government and state and territory governments are working together to develop energy performance assessments for existing homes. 

  • Work is underway to expand the Nationwide House Energy Rating Scheme (NatHERS) to include existing homes, with ratings to be available from mid 2025.
  • Residential Efficiency Scorecard assessments, which offer an alternative way of assessing the energy performance of an existing home, are available now.
  • The Commonwealth Scientific and Industrial Research Organisation (CSIRO) is developing RapidRate, an artificial intelligence powered tool for quickly estimating the energy ratings of homes using fewer inputs.

Expanding NatHERS ratings

In April 2023, the Australian Government announced funding to expand NatHERS to offer ratings for existing homes. Currently, the scheme offers ratings for new homes and major renovations.

The new energy ratings for existing homes will help Australian householders better understand their home’s energy performance, identify cost-effective upgrades to improve the comfort of their home, and reduce their energy bills.

The ratings will also give banks the confidence to loan more capital to Australians to upgrade the energy performance of their homes and help verify the loans as green investments.

An energy assessor will visit a home to take measurements and look at the construction and the building materials that have been used. The assessment will consider the comfort of the home in hot and cold weather extremes, and the energy used by major fixed appliances such as air conditioners, heaters and hot water systems. Like new home ratings, the assessment will provide both a thermal star rating (out of 10) and a ‘whole of home’ rating indicating the cost of running the home.

NatHERS ratings for existing homes will be available from mid 2025. Trials are planned for the second half of 2023 and into 2024 with the finance sector, property valuers and energy assessors.

Framework development

We are developing a program framework that will deliver a trusted, national scheme for rating the energy performance of existing homes.

Tools for assessing the energy performance of existing homes are being developed. CSIRO is developing a ‘benchmark tool’ for rating existing homes, which all other tools will be tested against.

To be accredited, other tools must be tested against the benchmark tool. The full requirements that tools must meet to be accredited are currently being developed, to ensure that all tools deliver consistent, reliable and accurate ratings that households and businesses can trust.

Tools alone are not enough to provide a reliable system for rating existing buildings. To ensure a mature and trusted framework for rating existing homes, we are developing robust technical guidelines and protocols, assessor accreditation arrangements, legal frameworks, and compliance and enforcement processes.

Residential Efficiency Scorecard

The Residential Efficiency Scorecard, which builds on the Victorian Government’s successful state-based program, offers NatHERS endorsed assessments of the energy efficiency of existing homes.

Scorecard assessments are available now. The assessments rate your home’s energy use and comfort and provide tailored recommendations for improvements.

While endorsed by NatHERS, the Scorecard is not currently accredited under NatHERS and cannot provide a NatHERS assessment.

However, endorsement provides an early indication that the tool, training and accreditation process demonstrate alignment with what NatHERS assessments of existing homes are expected to require in the future. Some amendments are expected as the requirements for existing homes are agreed and finalised.

To be accredited under NatHERS, the Scorecard will need to meet all the requirements that are currently being developed for existing homes.

The Scorecard assessment tool, assessor training and assessor accreditation are being delivered by the Victorian Government on behalf of all Australian governments.

Get a NatHERS endorsed Residential Efficiency Scorecard assessment.


Residential Efficiency Scorecard assessments are delivered by trained, government-accredited assessors. Assessors are energy efficiency experts who provide households with a simple pathway to achieve their goals, such as reducing their energy costs and carbon emissions or making their home all-electric, all while making their home more comfortable.

A Scorecard assessor visits a home to undertake an assessment, then provides a certificate with an energy rating and advice on what improvements can increase the energy performance of the home. The cost of an assessment is set by the assessor, and typically ranges from $250 to $500. Financial support to offset the cost is available in some areas.

Learn more about becoming a Residential Efficiency Scorecard assessor. 


CSIRO is developing RapidRate which is an artificial intelligence powered tool that estimates energy ratings for existing homes. RapidRate is not NatHERS accredited and does not provide a full NatHERS assessment or rating. Instead, RapidRate provides an estimate of the NatHERS rating and energy required for heating and cooling, based on the results of past NatHERS assessments.

RapidRate will require fewer inputs than a full NatHERS assessment, will be quick to do, and will not require special training. This means homeowners will be able to get a snapshot of the energy performance of their home, before seeking additional advice from a NatHERS or Residential Efficiency Scorecard assessment where required.

CSIRO is undertaking a trial of RapidRate in 2023 with the housing data provider, CoreLogic. The insights will initially be available to CoreLogic’s banking and finance customers, with plans to make RapidRate available to all Australians in the future.

See more on the Australian Housing Data portal and the CSIRO research website.