Granny Flat: Elemental Deemed to Satisfy

Region: All States

Assessor Question:

I'm chasing some clarification regarding a new dwelling I'm providing an energy rating report for.

There is a proposed separate bedsit/granny flat on the property that is not connected to the main building. It consists of a rumpus, store room, bedroom, ensuite & WIR. (no kitchen)

Is it your expectation that a separate energy rating is completed for this proposed building?

TechLink Response:

• NatHERS software cannot be used because the proposed granny flat has no kitchen.
•  The alternative approaches in this case are Elemental Deemed to Satisfy or Performance Solution.
• The two Deemed to Satisfy pathways in NCC vol 2 for Class 1a dwellings, being main wings with a kitchen or satellite wings without a kitchen, are Elemental DtS and NatHERS DtS. 
• The Elemental DtS approach is less flexible than a NatHERS DtS assessment due to the inability to balance under performance of any element against over performance of another.
• If the DtS approaches are unsuitable for some reason it is possible to use a Performance Solution or Expert Opinion to confirm that a design exceeds or is at least equal to the result that would achieve regulatory compliance with one of the two DtS methods.
• The ABCB provides good guidance as to what is required for non-DtS methods to give a Building Surveyor/Certifier confidence that the design achieves a suitable level of performance.
  https://www.abcb.gov.au/resource/infographic/performance-solution-process-overview