There are three methods of compliance for new residential dwellings:
- Deemed to Satisfy Elemental Provisions,
- NatHERS 6 Star Energy Rating, and
- Verification Method, using a Reference Building.
1. Deemed to Satisfy (DTS) Elemental Provisions
The DTS Elemental Provisions are listed in the NCC Volume 2 and the design must meet the minimum requirement for each individual aspect of design (floor, roof / ceiling, walls, glazing and lighting to name a few).
The DTS method is suitable for some designs but can be limiting, with glazing in particular. Some designs are not able to meet compliance with this method.
2. NatHERS 6 Star Energy Rating
The NatHERS 6 Star Energy Rating is where the dwelling is modelled in a NatHERS accredited software to rate the thermal performance of a home, based on its building fabric & design. This is the most popular method of compliance for new dwellings and with good reason.
3. Verification Method using a Reference Building (VURB)
The verification using a reference building assessment is where a reference building is modelled in energy software in an as compliant state with the DTS Elemental Provisions. The proposed building is then modelled trading off certain aspects against one another (e.g. better glazing for less insulation) and if the assessor can demonstrate that the proposed building energy consumption is not higher than the reference building, it’s considered compliant using this performance solution method.
VURB’s were a popular compliance option (especially in WA) up until the release of NCC 2019 where they created more stringent requirements surrounding this option, as some energy assessors were using this method to approve building designs that were not meeting the minimum energy efficiency requirement intentions of the NCC.
The Verification Method can still be used, however the NCC now outlines in more detail the way the reference and proposed buildings needs to be modeled and the modelling cannot be done using a NatHERS Software like it previously could.
In some circumstances, the Verification Method is still a good option for compliance in lieu of the NatHERS 6 Star Rating, however, homes will still meet around the same level of thermal efficiency as a NatHERS 6 Star Rated dwelling would.
If you would like to find out more about any option listed above, or book in your property for compliance reporting, contact us below.