This page will keep you informed about current work to expand the Nationwide House Energy Rating Scheme (NatHERS) to include existing homes from mid-2025.
For an outline of NatHERS for existing homes and the broader elements of its staged release see existing homes.
Stage 1 Assessor training and accreditation
To ensure a controlled and sustainable scale-up of NatHERS for existing homes, assessor training and accreditation will only be available to targeted groups until Stage 2. See the Assessor Toolkit for more information.
From mid-2025, at the commencement of Stage 1:
- Accreditation services will be delivered by the NatHERS Administrator. This will allow procedures and policies to be refined prior to the scale-up of accreditation services through a third-party provider.
- Accreditation will focus on assessors who participated in the trial of NatHERS for existing homes. It will also focus on those involved in the NSW home energy ratings disclosure pilot.
This approach means there will be a limited pool of trained and accredited energy assessors during Stage 1. It also means energy assessments of existing homes will be limited during this first stage.
Scale up Assessor training and accreditation
From early 2026, during the scale-up period:
- assessor accreditation is expected to transfer from the NatHERS Administrator to a third-party service provider
- training and accreditation is expected to be made available to additional target groups. This includes assessors that are already undertaking home energy assessments, such as NatHERS for new homes, Residential Efficiency Scorecard and the ACT Energy Efficiency disclosure scheme.
Stage 2 Assessor training and accreditation
From mid-2026, stage 2 of NatHERS for existing homes is expected to commence. At this point, training and accreditation will become available to other prospective assessors.
Information for Scorecard assessors
The Scorecard will continue alongside NatHERS for existing homes during the scale-up period. This provides time for assessors to train and become NatHERS accredited. It also provides time for assessors to make any required changes to their businesses. Scorecard assessors and users will have advance notice of any changes.
There will be ongoing support during the transition. This will include a streamlined pathway for Scorecard assessors to become accredited NatHERS for existing homes assessors.
Visit the Scorecard website for more information about the upcoming transition.
Stage 1 first generation software tool release
The first generation NatHERS for existing homes benchmark tool is now available for assessor use. It is the CSIRO-developed software tool AccuRate Enterprise (existing homes mode).
AccuRate Enterprise is supported by the commercial, third-party data collection tool magicplan.
Magicplan is not mandatory to complete an assessment and is not NatHERS accredited. Magicplan has been customised by CSIRO to export data into AccuRate Enterprise (existing homes mode). This reduces time on and off-site during an assessment. It has been used during the NatHERS trials.
NatHERS for existing homes also provides for the accreditation of third-party tools. A user interface protocol and associated terms and conditions have been released as part of Stage 1. These documents:
- establish the requirements for third-party software tools to become accredited
- enable commercial and third-party providers to commence development of software tools.
Stage 2 second generation software tool release
A second generation benchmark tool, assessment method and User Interface Protocol will be released as part of stage 2. This is expected to occur from mid-2026.
The second-generation release is expected to include modifications and enhancements. These will be based on the NatHERS field trials, Home Energy Ratings Disclosure Pilot, and any additional necessary changes. The main emphasis is expected to be on improving the assessor user experience. Adjustments to calculations or other processes will also be implemented as needed.
New and updated policies, procedures and governance documents
A range of new and updated documents are now available.
These include:
- NatHERS for Existing Homes Assessor Code of Practice - Describes the key requirements assessors must comply with to maintain their accreditation.
- NatHERS for Existing Homes Assessor Character Check Policy - Describes the character checks performed as part of the assessor accreditation process.
- NatHERS for Existing Homes Assessor Conflict of Interest Policy - Outlines the requirements for assessors to manage conflicts of interest.
- NatHERS for Existing Homes Assessor Performance Management Policy - Outlines how assessor performance issues are managed.
- NatHERS for Existing Homes Mentoring Policy - Sets out the requirements for, and role of, mentors in improving the performance of assessors.
- Complaint Management Policy - Describes how complaints about NatHERS can be made and how they are managed.
- NatHERS for Existing Homes Assurance Strategy - Establishes the approach to managing assessor errors, non-compliance, fraud, or other misconduct.
- Existing Homes Technical Note - Sets out the requirements that must be followed when conducting an assessment.
- NatHERS for existing homes Guidance Note. - Supports assessors to navigate the assessment process.
- NatHERS for Existing Homes User Interface Protocol - Provides the requirements for third-party UI tools using AccuRate Enterprise (existing homes mode).
Existing homes consultation
A targeted consultation on the expansion of NatHERS to existing homes ran throughout August 2024.
Feedback received through the consultation process helped shape the design of the scheme. It was considered by Energy and Climate Change Ministers in 2025.
The consultation paper and stakeholder submissions are available on the DCCEEW consultation hub.
You can access the webinar recordings and transcripts of the consultation sessions using the links below:
- Webinar 1: Consumer experience – Transcript (Docx)
- Webinar 2: Assessor services – Transcript (Docx)
- Webinar 3: Energy Rating tools – Transcript (Docx)
Technical and policy documents that underpin the delivery model are available below. Note: consultation closed on these documents on 30 August 2024. If you had issues submitting your feedback at the time, or have missed the cut off, please contact admin@nathers.gov.au.
Assessor Accreditation Requirements Draft - released 12 August 2024
Assurance Strategy Draft - released 12 August 2024
Email us with any feedback and questions.
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 keep an eye on our Assessor Toolkit. It will be updated with information on becoming trained and accredited as a NatHERS for existing homes assessor.