NatHERS Existing Homes

Currently NatHERS provides an assessment and rating about the thermal performance (heating and cooling needs) of a home’s construction. These assessments are generally used for new homes and major renovations.

Soon NatHERS will also provide information about the overall energy performance of the home, including appliances and renewable power generation.

An assessment and rating for an existing home will provide information about the thermal performance, appliances and renewable power generation, and also provide the additional benefit of being able to identify what improvements can be made after the home has been built.

To support the delivery of home energy ratings for existing homes under NatHERS, a Scoping Report was developed. This report found the option to extend NatHERS to existing homes, while continuing to test and learn from the national version of the Residential Efficiency Scorecard, is the most efficient and effective use of resources.

Work is now underway to establish NatHERS protocols and processes for existing home assessments. This includes further testing and refining of the national version of the Residential Efficiency Scorecard, so that it may be accredited under NatHERS. Following a transition period, any tool operator in the market may then develop other energy rating tools for existing homes and seek accreditation under NatHERS.

The first version of the requirements for NatHERS to be extended to existing homes is due to be finalised in mid-2021, following analysis and stakeholder consultation.

For more information about the importance of having energy ratings and tools, see the Trajectory for Low Energy Buildings