VURB using NatHERS softwares

Region: Queensland

Assessor Question:

I would like some confirmation if the VURB assessment is still accepted using NatHERS software in Qld.

We have come across a few reports now that certifiers are accepting and need clarification asap and we are losing a few clients over this matter 

TechLink Response:

• In July 2017 the CSIRO released a statement advising that NatHERS software was not suitable for use in the completion of a VURB report in compliance with V2.6.2.2 as NatHERS software uses a different set of conditions to those set out in the NCC.
  
• The situation has not changed but not all Certifiers/Building Surveyors are fully aware of the limitations. When it becomes apparent that the practice is still persisting it should be drawn to the attention of the practitioners that the assessment will not be compliant with NCC performance standards.
  
• If a NatHERS accredited Assessor is preparing these assessments, they would be at risk of breaching the Accreditation Code of Conduct for breaching the NatHERS protocol.

• House energy rating software, including software accredited or previously accredited under the NatHERS, as well as the additional functionality provided in non-regulatory mode, is not permitted to be used for complying with V2.6.2.2.
• This exclusion is the result of feedback from stakeholders about the misuse of NatHERS software in conjunction with V2.6.2.2 and a number of areas of V2.6.2.2 being gamed.
• V2.6.2.2 was first introduced into the NCC to enable the use of non-NatHERS software to assess the energy efficiency of houses.
• In most instances NatHERS software could not comply with the requirements of V2.6.2.2, specifically in relation to the modelling of temperature settings, and potentially air infiltration and internal heat gains.