Australian governments are working together to deliver energy ratings for existing homes. To do this the Nationwide House Energy Rating Scheme (NatHERS) is being expanded. Previously, NatHERS has only been available for rating new homes and major renovations.
The ratings include:
- a thermal assessment, based on how much heating and cooling the home needs to stay comfortable. This considers a home’s design, orientation, insulation and construction materials.
- an assessment of the energy the home will use. This is based on its major fixed appliances, thermal performance and on-site solar generation and storage.
There are expected to be a range of users of NatHERS for existing homes ratings:
- households can better understand their home’s energy performance and use the practical guidance included with the assessment to make improvements to their home and cut energy bills.
- banks may use the ratings to verify green loans, helping them access green capital markets to lend money for home upgrades. This will drive energy performance improvements in existing housing stock.
- in time, jurisdictions may use the ratings to underpin home energy rating disclosure schemes at the point of sale or lease.
- various businesses will benefit from new business opportunities, jobs and professional development to meet the demand for skills, services and products to rate and improve energy performance.
Rolling out existing home energy ratings
A staged approach to expand NatHERS has commenced. NatHERS for existing homes will initially be available to a small audience. This approach will ensure a well-managed roll out. It will also allow further refinement in collaboration with assessors, industry and delivery partners.
To meet a growing demand for existing homes ratings, a sustainable workforce scale-up is being implemented to increase capacity and improve assessment processes.
Stage 1
Stage 1 of the release of NatHERS for existing homes included:
- the release of a first-generation tool and assessment method
- publishing policies, procedures and governance documents
- opening accreditation to a limited pool of trained assessors.
Scale-up
A period of scale-up and learning-by-doing is now underway. This provides time to further refine processes, tools, and communications. During this period:
- training and accreditation services will be made progressively made available to target groups. These will include current energy assessors, such as NatHERS for new homes assessors, Scorecard assessors and ACT Energy Efficiency Rating assessors.
- a pilot of the Home Energy Ratings Disclosure Framework in NSW is being conducted. The pilot, and other initiatives that use NatHERS for existing homes, will inform further refinement of assessments ahead of the next stage of the rollout.
For more information about timing and specific details during this period, see expansion updates.
Stage 2
Stage 2 will commence following the integration of feedback and learnings from Stage 1 and the scale-up period. Stage 2 will improve NatHERS for existing homes and bring ratings to a wider audience. During Stage 2:
- a second-generation tool, assessment method and processes will be released
- accreditation will be opened to all interested assessors
- more opportunities will be provided for households to get an assessment.
Stage 2 is expected to commence from mid-2026.
Stay informed
We will continue to provide updates as they become available.
Sign up for the NatHERS newsletter for alerts about expansion updates.
Assessors should read our expansion updates page and keep an eye on our Assessor Toolkit. These will be updated with information on becoming trained and accredited as a NatHERS for existing homes assessor.
Households interested in getting an existing home rating should be aware that the availability of assessors is currently very low. Stage 2, from mid-2026, will offer more opportunities for households. You may use the assessor register to contact assessors independently for assessments and are encouraged to seek multiple quotes.
Trial
A field trial is underway on the tools and processes used to rate the energy performance of existing homes. The trial, which is being conducted from late 2024 to late 2025, is a partnership between the Department of Climate Change, Energy, the Environment and Water and CSIRO, on behalf of all states and territories.
Visit the trial page for more information.
A delivery model for existing homes ratings
In March 2025, Energy Ministers agreed the model for delivering NatHERS to existing homes. It is designed to provide reliable, consistent and comparable ratings for existing homes. It will also reduce administrative complexity and manage risk.
The feedback from a consultation in August 2024 shaped the delivery model. Over 40 submissions were received from assessors, community and industry groups. A series of webinars were also attended by 750 people.
Find out more about the consultation on expansion updates.
NSW Home Energy Rating Disclosure Pilots
The NSW and Australian governments will conduct a pilot of the disclosure of home energy ratings in late 2025 in close collaboration with the real estate sector. This pilot, also referred to as the NSW trial, will focus on disclosure during the sale or lease of a home.
The pilot will test the nationally agreed systems outlined in the Home Energy Ratings Disclosure Framework. This includes:
- developing and testing training content and resources for real estate agents
- testing and refining content and resources for consumers
- evaluating the experiences of individuals involved in the sales and lease processes.
Findings from the pilot will inform the NSW Government about when to transition to mandatory disclosure of ratings at point of sale or lease. They will also help other states and territories considering home energy ratings disclosure.
Details about the pilot will be shared via the newsletter closer to its start date.
ACT EER Disclosure Scheme obligations
NatHERS for existing homes ratings are not compatible with the current legislated requirements of the Australian Capital Territory (ACT) House Energy Rating Scheme (the scheme). The scheme is also known as the Energy Efficiency Rating (EER) Disclosure Scheme. The scheme has specific requirements for their software, assessors and certificates.
The ACT Government is closely monitoring the development of the NatHERS for existing home program. They may consider whether it could be incorporated into ACT disclosure legislation in the future.
Residential Efficiency Scorecard
The Residential Efficiency Scorecard program rates a home’s energy use and comfort and provides tailored recommendations for improvements. The program consists of the Scorecard assessment tool, assessor training and assessor accreditation. It is being delivered by the Victorian Government on behalf of all Australian governments.
The Scorecard was a successful first step in providing energy ratings for existing homes.
The NatHERS expansion is the next stage in rating existing homes and will help align ratings for existing homes with ratings of new homes. NatHERS is being shaped by Scorecard experiences. It is also being improved based on feedback from households, stakeholders and governments.
There will be an extended transition from Scorecard to NatHERS for existing homes, with advance notice before any changes. During this time, Scorecard assessments will still be available.
Sign up for the NatHERS newsletter to get expansion updates, and visit the Scorecard website for more information about the upcoming transition.
RapidRate
Another tool developed by CSIRO and providing estimated energy ratings for existing homes is RapidRate.
RapidRate is an artificial intelligence (AI)-powered tool. It estimates energy ratings for existing homes. The tool is not NatHERS accredited and does not provide a full NatHERS assessment or star rating. Instead, RapidRate provides an estimate of the NatHERS rating, and the energy required for heating and cooling. It is based on the results of past NatHERS assessments.
RapidRate uses a simplified set of inputs and is designed to be used to rate large property portfolios quickly. It is less accurate for individual homes and is not a replacement for a NatHERS assessment.
In 2023, the Australian Government provided CSIRO funding to undertake a trial of RapidRate with the housing data provider, CoreLogic. The trial insights will initially be available to CoreLogic’s banking and finance customers.
Visit the Australian Housing Data portal and the CSIRO research website for more information.