Benchmark tool

The benchmark tool (AccuRate Home) is supporting the expansion of NatHERS to include Whole of Home assessments and ratings.

The NatHERS Administrator uses the benchmark tool to measure the accuracy of software tools seeking NatHERS accreditation. This ensures outputs are consistent across all accredited tools.

CSIRO released the consultation version of the benchmark tool in March 2021. Since then, a range of updates and improvements have been made. These updates have been undertaken in partnership with industry and government experts. This includes enhancements identified through the National Construction Code (NCC) 2022 consultation process. Interested tool developers can access the calculations method used to develop the benchmark tool here.

The benchmark tool provides an assessment and rating of a home’s appliances and has been designed to align with the NCC 2022 energy efficiency performance requirements.

  • It includes the key regulatory appliance modules included in NCC 2022 (heating and cooling appliances, hot water systems, swimming pool and spa pumps, lighting, onsite solar photovoltaic (PV) and battery systems) as well as allowances for non-regulated loads (such as plug-in appliances and cooking loads). This allows NatHERS tools to be used for NCC 2022 as well as provide valuable information to users about energy use across the whole home.
  • Within each appliance module, the tool provides a larger range of appliance types than offered under the NCC 2022 elemental pathway.
  • It calculates the annual energy use of a home (by fuel type), solar PV generation and battery storage, electricity imports and exports.
  • It provides a breakdown of energy use by module so that users can see what is having the largest impact on energy use.
  • It provides a Whole of Home rating based on the energy value of the home (the metric used for NCC 2022).

A commercial version of the NCC 2022 compliant AccuRate is available from Energy Inspection.

Watch the Whole of Home benchmark tool demonstration video

Endorse NatHERS Whole of Home tools

Please refer to the software updates page for the most up to date information on endorsed NatHERS Whole of Home tools.

Accredited Software

All software used to produce NatHERS energy ratings must be accredited in accordance with the NatHERS Software Accreditation Protocol.

There are currently four software tools accredited for use under NatHERS for demonstrating compliance to NCC 2019, all are based on the CSIRO calculation engine, Chenath (v3.21):

Key modelling inputs

To ensure calculations are accurate, representative of Australian conditions and are comparable across different types of housing, the Software Accreditation Protocol requires all accredited software tools to meet strict performance standards.

Some of these performance standards include:

CSIRO’s Chenath calculation engine

The Chenath engine has been developed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO). It uses decades of climate data and average user behaviour, among other factors, to predict annual totals of hourly heating and cooling energy requirements for residential dwellings. More information on the Chenath engine can be found in the Chenath repository.

Although it is not a requirement of accreditation, currently all NatHERS accredited software use the Chenath engine to perform the calculations and modelling for a home energy rating.

The Chenath engine was validated in 2004 against the international standard ANSI/ASHRAE 140-2001.

For more information read the Validation of the AccuRate Simulation Engine Using BESTEST.

Including new materials in NatHERS software tools

The Technical Advisory Committee (TAC) periodically meets to consider whether new materials and products should be included in the databases of the NatHERS accredited software tools. As with software updates, the TAC’s recommendations are provided to the NatHERS Steering Committee for approval before the new materials are included.

WERSLink Library

Plans to integrate the new WERSLink window libraries into NatHERS software continues to progress well despite complex technical challenges causing some unforeseen delays. 

The team is prioritising the project with support from the Australian Glass & Window Association (AGWA), who are also reviewing and advancing the required legal agreements, to ensure the WERSLink window libraries are embedded into all NatHERS software as soon as possible.

The new WERSLink Default Window Library is now available for regulatory use in AccuRate Home’s latest release v1.3.3.23 SP2. This new default library exists alongside the current NatHERS Default Window Library, and can be used as an alternative.

For more information and guidance see the NatHERS Assessor Handbook and Technical Notes and your software's technical support manual. 

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