Print

Clarification: NatHERS for alterations and additions

Clarification on whether NatHERS assessors are appropriately qualified to provide input to performance solutions for the energy efficiency of alterations and additions.

The VBA has become aware of differing interpretations of whether Nationwide House Energy Rating Scheme (NatHERS) assessors are appropriately qualified to provide input to performance solutions for the energy efficiency of alterations and additions.

When using NatHERS software to determine compliance with energy efficiency requirements in the National Construction Code (NCC) and the NatHERS rating is less than 6 stars, it is a performance solution rather than a Deemed to Satisfy (DTS) solution. If the home achieves a 6 star NatHERS rating or above, then NatHERS can be used as a DTS solution.

The Australian Building Codes Board (ABCB) has recently published updated guidance about the performance solution process. The guidance states that relevant design process practitioners, such as Environmentally Sustainable Design specialists, can be involved in the development of a performance solution.

It should also be noted that NatHERS Accredited Assessors must meet standards set out in the Accredited Assessor Organisation (AAO) Protocol, which is managed by the NatHERS Administrator on behalf of all states and territories. These requirements include:

  • A Cert IV qualification in either NatHERS Assessment or Building Energy Efficiency and Sustainability, as well as training in the nominated software used by the assessor.
  • Membership of, and accreditation by, a NatHERS Assessor Accrediting Organisation.
  • Professional Indemnity Insurance.
  • Adherence to the Code of Conduct of their accrediting organisation
  • Each year, AAOs undertake a Quality Assurance review of 20 per cent of their Accredited Assessors under a process agreed with the NatHERS Administrator.
  • Participation in annual Continued Professional Development.

NatHERS Accredited Assessors will be subject to disciplinary action and may lose their accreditation if they fail to meet these requirements.

Considering their role in determining the star rating of a home, it would be appropriate to consider NatHERS Accredited Assessors’ expertise when developing performance solutions for alterations and additions in order to comply with residential energy efficiency requirements in the NCC.