SA residential energy rating: NCC 2022 Modern Homes and the 7-star NatHERS transition

What it is

The National Construction Code (NCC) 2022 introduced the Modern Homes provisions: a step up from a 6-star to a 7-star Nationwide House Energy Rating Scheme (NatHERS) thermal performance requirement, a new whole-of-home annual energy use budget and updated liveable housing design accessibility provisions. South Australia commenced the Modern Homes provisions on 1 October 2024, later than most other states. The delay reflected SA-specific concerns about market capacity, small and narrow blocks, and tourist accommodation.

In South Australia, the NCC is applied by the Building Code, which is the NCC as varied by SA-specific Ministerial Building Standards (MBS). MBS 007 is the primary modifications document. MBS 013 sets out how Modern Homes provisions apply to new work on existing Class 1 buildings. The Department for Housing and Urban Development publishes the current MBS suite through the PlanSA portal.

What the 7-star rule requires

For new Class 1 dwellings (single houses and townhouses), the NCC 2022 sets a minimum NatHERS thermal performance rating of 7 stars. The rating measures predicted heating and cooling energy intensity using accredited NatHERS software run by a registered assessor. The annual energy use budget then sets a cap on the predicted whole-of-home energy use, calculated from the thermal performance, water heating, lighting and (where present) pool and spa equipment.

The 7-star rating is harder to hit than 6 stars on the same footprint. Designers commonly respond with improved wall and ceiling insulation, double glazing in cold and hot climates, careful eaves design, slab edge insulation and tighter air sealing details.

What SA varies

The SA Government delayed Modern Homes by 12 months beyond the national target to give the industry time to retool. Transitional rules then applied. Any development application for a house or apartment lodged before 1 October 2024 is assessed under NCC 2019. From 1 October 2024 onwards, new lodgements fall under NCC 2022 as modified by the current MBS 007.

A separate concession allows development applications for alterations and additions to an existing house lodged before 1 May 2026 to be assessed for energy efficiency under NCC 2019. After 1 May 2026, alterations and additions must meet the Modern Homes provisions as adapted by MBS 013.

Liveable housing design

Modern Homes also brings in the silver-level liveable housing design provisions for Class 1a buildings: step-free path of travel, reinforced bathroom walls and a doorway clear opening width that supports future accessibility upgrades. These provisions apply alongside the 7-star and whole-of-home energy budget.

Compliance pathway

A NatHERS thermal assessment, completed by an assessor accredited through a registered Assessor Accrediting Organisation (AAO), is the standard pathway. The assessor produces a certificate that lists the star rating and the whole-of-home result. The building rules consent application is lodged through PlanSA with the NatHERS certificate attached.

Where the design will not reach 7 stars through deemed-to-satisfy means, a Performance Solution can be developed by a competent practitioner under NCC Volume Two A2G1. Performance Solutions require evidence of suitability and are signed off by the relevant building consent authority.

How TradeLens uses this

TradeLens reads the NatHERS certificate, the application lodgement date and the MBS version applied to the design. If the design pre-dates 1 October 2024 lodgement but construction is now underway, TradeLens confirms the saved-NCC-2019 pathway is documented. If the certificate shows a rating below 7 stars without a Performance Solution attached, the file is raised for review. The same logic applies to alterations and additions sliding past the 1 May 2026 cut-off.

Common pitfalls

• Assuming a NatHERS certificate from a 6-star design can be reused for a near-identical 7-star build. The model has to be rerun with the current rules.
• Forgetting the whole-of-home budget. A high-performing envelope can still fail compliance if the hot water system, lighting or HVAC pushes the predicted annual energy use above the cap.
• Treating MBS 007 as static. Versions have been superseded several times. Always pull the current version from PlanSA before lodging.
• Quoting an alterations and additions job with a 1 May 2026 lodgement deadline without an internal cut-off built into the program. A late lodgement loses the NCC 2019 concession.

What to do

Confirm the application lodgement date against the operative NCC and MBS versions. Brief the NatHERS assessor early in the design phase so the rating informs the envelope. Keep the assessor's certificate, the MBS version reference and any Performance Solution evidence together in one compliance pack for the build file.