NatHERS 2022 Whole of Home - Overview

Download the PDF of Whole of Home - Overview

The Nationwide House Energy Rating Scheme, or NatHERS, is being expanded to include Whole of Home assessments and ratings to support the proposed National Construction Code energy efficiency requirements for residential buildings in 2022. The changes will help households improve a home’s energy efficiency and reduce energy use, which provides a range of benefits including lower energy bills, improved comfort and health for occupants, and reduced carbon emissions.

NatHERS thermal assessments provide a rating (out of 10) and information about the thermal performance (heating and cooling needs) of a home’s construction. The thermal assessment is based on information about the home’s design, construction materials and the climate where it is being built.

NatHERS is expanding from a thermal performance rating to also include information about the energy performance of common household appliances, such as heating, cooling, hot water, lighting, pool/spa pumps and on-site energy generation and storage (e.g. solar panels and batteries).

The NatHERS Whole of Home benchmark tool is supporting the expansion of NatHERS to Whole of Home assessments and ratings. These and other improvements to the tool are currently under development, to be ready in time to support NCC 2022 requirements.

Watch the Whole of Home benchmark tool demonstration video.

Benchmark Tool

CSIRO released the consultation version of the NatHERS Whole of Home benchmark tool (AccuRate) in March 2021. The benchmark tool measures the accuracy of other Whole of Home tools seeking NatHERS accreditation to ensure outputs are consistent across all accredited tools. This is the same approach taken for NatHERS thermal accredited tools.

For access to CSIRO’s consultation version of AccuRate email:

Please note that you need to be proficient in AccuRate to use the benchmark tool.

The benchmark tool enables an assessment of a home’s appliances and has been designed to align with the proposed NCC 2022 Whole of Home performance requirements:

  • The consultation version includes the key regulatory appliance modules to support the proposed changes for NCC 2022. This includes, heating and cooling appliances, hot water systems, swimming pool and spa pumps, lighting and onsite solar photovoltaic (PV) systems.
  • It generates the annual energy use of a home (by fuel type), solar PV generation, electricity imports and electricity exports.
  • It provides a breakdown of energy use by appliance so that users can see what is having the largest impact on energy use in the design.

Further work is being undertaken in partnership with industry and government experts to enhance the NatHERS Whole of Home benchmark tool and streamline the Whole of Home assessment process. This will include enhancements identified through the NCC 2022 consultation process.

The ABCB is seeking feedback on the proposed energy efficiency provisions for NCC 2022. To have your say go to the ABCB Consultation Hub.

For more information on the development of Whole of Home go to the NatHERS Whole of Home About page.

Software developers can express their interest to be endorsed by the NatHERS Administrator. Endorsement provides an early indication that the tool may be accredited in the future.

For more information about the expression of interest and endorsement process, find out more here.

Currently Endorsed NatHERS Whole of Home tools

The NatHERS Administrator has endorsed Sustainability Victoria’s FirstRate5 Whole of Home Pilot Tool. For more information, please visit Sustainability Victoria’s website.

In the future, it is expected that other Whole of Home tools will become accredited under the scheme.

Draft Whole of Home NatHERS Certificate

A new NatHERS Certificate is being developed to support the proposed NCC 2022 energy efficiency provisions.

The new Certificate will continue to include a thermal performance star rating out of 10 to demonstrate compliance with the proposed NCC 2022 Performance Requirement 1. It will also include a new Whole of Home rating out of 100 to demonstrate compliance with the proposed NCC 2022 Performance Requirement 2. This Whole of Home score combines the thermal performance with the energy performance of the home appliances and energy generation and storage.

These changes will help households understand their home’s overall energy performance, helping them improve the comfort of their home and reduce their energy bills..

Whole of Home Certificate (PDF 2MB)

Example NatHERS certificate

New Certificate Features:

  • A new NatHERS Whole of Home performance rating to demonstrate compliance with the NCC’s PR2
  • A new approach to displaying split heating and cooling load limits
  • An expanded checklist for verifying the home is designed and then built according to the information used to create the NatHERS ratings
  • New schedules for appliances. These include detailed information about the home’s appliances, onsite renewable energy and battery systems
  • Other supporting information such as renewable energy contributions, greenhouse gas emissions, cost and energy consumption breakdowns for the energy uses in the home.

The update to NatHERS to include Whole of Home assessments and ratings will be gradually phased in. Over the next 2 years we will work through 4 phases to develop, establish, release and modify these updates.

The expanded Whole of Home scheme is expected to be fully operational by September 2022, to support the potential changes to the NCC 2022.

Visit the NatHERS Whole of Home page for more detailed information on the roll out of Whole of Home assessments.