News

Implications of updates to energy rating software

FirstRate5 is the most widely used NatHERS energy rating software in Victoria. Commencing on the 1st of February, 2015, accreditation for a new version of FirstRate (version 5.2.0) was granted. This update brings FirstRate5 in line with recent updates to the Chenath thermal modelling engine which is used by all NatHERS software to calculate heating and cooling loads (projected annual heating and cooling energy usage).

The new version of FirstRate5 is more accurate, which means it will reward dwelling designs that have good ESD principles built in. In addition, there is a new Technical Note with specific requirements which we need to comply with, and which the BDAV audits us on to ensure the integrity of the scheme. EcoResults has commenced using the new version on all new energy ratings for single dwellings, apartments and townhouses.


There are a few key implications which we want to make our clients aware of:

  1. The new software may require specifications (glazing and insulation) that are different than what you are used to. For some designs, the specification of insulation and glazing may increase with the new version of FirstRate5. If you'd like to discuss ways of improving your designs to reduce the amounts of insulation and the specification of high end glazing in order to achieve the required 6 star rating, please contact us.
  2. The additional software and Technical Note requirements creates additional complexity and takes an increased amount of time to model.
  3. The NatHERS administrator will endeavour to give us 30 days notice of the date when the old version of the software will have its accreditation withdrawn. If you have had us conduct energy ratings on any project prior to February 1st this year, but have not yet issued the final working drawings for us to stamp, please contact us ASAP, so that we can complete the certification and stamping process prior to the expiry of the old software. If we are not able to stamp and certify the ratings with the old software prior to its expiry, we will need to re-model and/or update the ratings in the new version of the software, which will result in additional fees and possibly increased insulation and glazing specifications.