The Australian Government is expanding the Nationwide House Energy Rating Scheme (NatHERS) to include assessments for existing homes. NatHERS previously offered energy ratings only for new homes and major renovations.

Energy ratings are completed by accredited energy assessors, who visit private properties to collect information and generate a Home Energy Rating Certificate using NatHERS software.

Under requirements set by the NatHERS Administrator, one or more assessor accreditation service providers are required to accredit assessors and manage their ongoing accreditation. They will ensure that only appropriately trained and qualified assessors who abide by a code of practice and meet ongoing professional development and performance requirements may deliver energy ratings to homeowners.

Key service provider activities include:

1. accrediting assessors, including processing applications for accreditation and managing the annual extension of accreditation, in accordance with standards established by the NatHERS Administrator

2. managing the continuing professional development, quality assurance and performance of assessors

3. managing enquiries and complaints from and in relation to assessors

4. establishing required services and processes, such as an assessor management system, a digital platform, and operational policies and procedures; and

5. keeping full and accurate records and providing regular reporting to the NatHERS Administrator.

A staged approach to introducing NatHERS for existing homes commenced from July 2025. NatHERS ratings of existing homes will be voluntary initially and will start with a small pool of assessors, increasing over time as ratings are incorporated into private sector and government programs and offerings.

By accrediting assessors, the assessor accrediting service provider will contribute to the aims of the expansion of NatHERS to existing homes:

• Helping householders better understand their home’s energy performance and to make cost-effective decisions to improve the comfort of their home and reduce energy bills.

• Giving banks and other financial institutions more confidence to loan money for home energy performance upgrades and supporting them to verify those loans as green investments.

• Supporting home energy rating disclosure requirements at point of sale or lease, if implemented by state and territory governments.

More information about NatHERS and the expansion to existing homes can be found at www.nathers.gov.au.