- Owners and Builders
All energy rating software used to produce NatHERS energy ratings must be accredited in accordance with the NatHERS Software Protocol.
The NatHERS Software Accreditation Protocol outlines the requirements and processes for the accreditation of new software tools and for updates to new versions of previously accredited tools. This ensures that software tools meet standard requirements and produce consistent results in the assessment of energy loads and when rating houses.
There are currently three software tools accredited for use under NatHERS:
For further information about the key accreditation requirements for NatHERS software see the NatHERS Software Protocol – Key requirements page.
Note to Council staff and Building Certifiers regarding version numbers for upgrades and bug‑fixes of NatHERS accredited software:
Any minor up-grades or bug-fixes to NatHERS accredited software using the same version of the Chenath Engine would, if approved, retain accreditation, however the suffix of the software’s version number would change.
For example, any further version where the ‘x’ changes (v4.3.0.x (3.13)) that version would have accreditation subject to confirmation by the National Administrator. This rule also applies to FirstRate5 v.5.2.x (3.13).
As NatHERS accredited software tools are privately owned it is the responsibility of each software developer to regularly update their accredited software tools in line with or better than minimum requirements set by the NatHERS Administrator.
To ensure that the NatHERS software tools (and CSIRO’s Chenath Engine) meet industry needs, the NatHERS Software Technical Advisory Committee (TAC), which includes representatives from each of the NatHERS Accredited Software providers and relevant Australian research and industry bodies, periodically meets to discuss potential updates and to prioritise relevant research activities. TAC recommendations are provided to the NatHERS Steering Committee for approval before implementation. Changes to the software are made considering:
If you have a specific update which you would like to be considered by the TAC, please contact the NatHERS National Administrator.
The TAC also periodically meets to consider whether any new materials and products should be included in the extensive product and material information databases built into each 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 can be included.
If you would like your product or material to be considered for inclusion in an upcoming database update, please contact the NatHERS National Administrator page.
Before applying, you should read the following documents to confirm your product is not similar to an existing generic brand already included in the software:
Although it is not a requirement of accreditation, currently all NatHERS Accredited Software tools are underpinned by CSIRO’s Chenath Engine. The Chenath Engine is used by each software tool to perform the calculations and modelling supporting each home energy rating.
The Chenath Engine has been developed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and is based on decades of scientific research on the way buildings operate in Australian conditions. It uses 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 calculations and assumptions can be found in the Chenath repository.
The Chenath Engine was validated in 2004 against the international standard ANSI/ASHRAE 140-2001. Results produced by the Engine were compared against the results from a set of international 'reference' programs and were found to meet the standard. For more information read the Validation of the AccuRate Simulation Engine Using BESTEST [PDF 34 KB].