Energy Rating Reports for 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 13 and Whole of Home Part 13.6. This is applied for either new dwellings or alterations/extensions.

This compliance option is located:

·       for houses, in the DTS Provisions of Volume Two H6D2(1)(a) and H6D2(2)(a)

·       for apartments, in the DTS Provisions of Volume One J2D2(2)(a) and J2D2(3)(a)(ii), (b) and (c).

New dwellings are typically assessed to satisfy the NATHERS 7-Star energy rating requirement. 

Source: Energy Efficiency Handbook NCC Volume 2

Compliance option 1: Energy rating

There are 2 existing main compliance options for houses now expanded to incorporate new WOH Deemed-to-Satisfy (DTS) Provisions. These options are shown in the diagram.

Source: ncc.abcb.gov.au

Compliance option 2: Elemental provisions

This option provides a prescriptive approach to complying with the housing energy efficiency Performance Requirements. The elemental provisions are in the DTS Provisions and when followed in their entirety form a DTS Solution.

This compliance option is located:

1. 1. for houses, in the DTS Provisions of Volume Two, H6D2(1)(b) and H6D2(2)(b), and
   2. for apartments, in the DTS Provisions of Volume One, J2D2(2)(b) and J2D2(3)(a)(i), (b) and (c).

The following figure outlines the relevant requirements that form the elemental compliance option. To meet the Whole-of-Home (WHO) requirements using this option, compliance with the WOH energy usage requirements is required. This is shaded purple in the figure below. This would cover: lighting, A/C efficiency, hot water unit, swimming pool and apa and on-site photovoltaics system.

Source: ncc.abcb.gov.au

Energy Reports for Alterations and Extensions - Assessment Pathways

Alterations and extensions may be assessed using one of the following methods, depending on the scale and nature of the works:

1. Alterations or extensions exceeding 50% of the existing dwelling volume
Where the proposed alteration or extension exceeds 50% of the existing building volume, the entire dwelling is generally required to achieve a minimum 7-Star NatHERS thermal performance rating.
In some circumstances, dispensations may be granted by the relevant building surveyor in accordance with Regulation 233.

2. Alterations or extensions less than 50% of the existing dwelling volume – Performance-based approach where the alteration or extension is less than 50%, two energy reports may be prepared:

• An energy rating for the overall dwelling (existing and proposed works) that includes reasonable upgrades to the existing dwelling, with the aim of achieving the highest practicable thermal performance rating; and
• A second energy rating for the overall dwelling (existing and proposed works) that excludes certain upgrades to the existing dwelling where these are not feasible.

This approach is consistent with VBA Practice Note EE-04 (Page 8). VBA Practice Note EE-04

3. Alterations or extensions less than 50% of the existing dwelling volume – Deemed-to-Satisfy (DtS) approach. As an alternative, alterations and extensions less than 50% may be assessed against the elementary (DtS) provisions of NCC Part 13. Under this pathway, building fabric elements associated with the works must meet the minimum NCC energy efficiency requirements. 

NCC 2022 Part 13 – Energy Efficiency elementary deemed-to-satisfy (DtS) Provisions.

Part 13.2 – Building Fabric

Part 13.4.4 – External Glazing

Part 13.4 – Building Sealing

Part 13.6 – Whole-of-Home Energy Efficiency

Part 13.7 – Services

 

Performance Solution P2.6.1 and P2.6.2 by Verification Method V2.6.2.2 (NCC 2019)

Performance Solution H6P1 and H6P2 by Verification Method H6V2 (NCC 2022)

Another method is Performance Solution by Verification Method as per NCC (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:

1. The function and use of the building and service.
2. The internal environment.
3. The geographic location of the building.
4. The effects of nearby permanent features such as topography, structures and buildings.
5. Solar radiation.
6. Building sealing envelope against air leakage.
7. Utilisation of air movement to assist cooling.
8. Domestic service.
9. The energy source.
10. Greenhouse gas intensity of heating energy; Energy from a renewable source.

BASIX Assessments (NSW)

Efficient Energy Choices provides BASIX assessments and certificates for residential developments in New South Wales. BASIX (Building Sustainability Index) is a mandatory planning requirement that ensures new homes and residential alterations meet minimum standards for energy efficiency, water efficiency, and thermal comfort. We work closely with homeowners, designers, and builders to prepare compliant BASIX assessments that integrate seamlessly with the building design, support Development Applications (DA) and Complying Development Certificates (CDC), and deliver practical, cost-effective sustainability outcomes.