Energy Rating Report Residential
6-Star Energy Rating Reports for new Dwellings
There are two ways to achieve compliance. One way which is most commonly used, is the Deemed-to-Satisfy (DtS) Method. This is as per the NCC Part 3.12. This is applied for either new dwellings or alterations/extensions.
New dwellings are typically assessed to satisfy the NATHERS 6-Star energy rating requirement. This method only assesses building fabric and excludes services and solar power panels.
Source: Energy Efficiency Handbook NCC Volume 2
Energy Reports for alterations/extensions
Alterations/extensions may also be assessed by the following methods:
Part 3.12 DtS Provisions for energy efficiency address the following:
Performance Solution P2.6.1 and P2.6.2 by Verification Method V2.6.2.2
Another method is Performance Solution by Verification Method as per BCA V2.6.2.2 (VURB - Verification Using a Reference Building Method). This method assesses the whole dwelling including building fabric, heating, cooling, services and other sources of renewable energy. It gives more flexibility and choice where the prescriptive DtS Provisions are considered to be too rigid or inappropriate in assessing certain building designs. Verification Method can allow for innovation and effective use of the building fabric to make the building more energy efficient. It takes into consideration the following items:
See below extract from VBA Practice Note.
The dwelling is assessed twice. The first assessment is for the reference building as required per NCC Part 3.12 DtS requirement. Then a second assessment is for the proposed dwelling. Compliance is achieved when the building efficiency for heating and cooling is equal or better than the reference dwelling. This approach requires two modelling runs with an approved NCC software and AHRAE Standard 140 compliant. The first is to set the heating and cooling load targets (i.e. using the reference building) and the second is to demonstrate that the proposed building can achieve this minimum target or better. The same calculation method is to be used in both model runs to maintain consistency.
The above procedure is from ABCB Handbook on NCC Energy Efficiency Volume Two. As an alternative assessment method, a project may have a solar power system on site to generate electricity and reduce Green House Emissions (GHG). This may be used to meet or supplement cooling and heating loads as noted in NCC Clause F2.6 (b)ii and Clause 4.3 of NCC Handbook on Energy Efficiency Volume Two. Solar power system loses will need to be allowed in the calculations.