Building energy standards

NCC, NatHERS and BASIX: Which One Applies?

The NCC sets building requirements. NatHERS is one way to model a home's energy performance and produce rating evidence. BASIX is part of the NSW planning process. Your project can involve more than one of them.

Reviewed 2026-09-01Written for household decisions. Official sources are linked below for rules and program details.
The short answer

Start with the project location and approval route

NatHERS

The assessment is based on coordinated plans

A new-home NatHERS assessment models the proposed home before construction. The certificate can include a thermal Star Rating and, where required, a Whole of Home rating for fixed energy systems.

The drawings, specifications and model must describe the same design. If windows, insulation, shading or fixed systems change, the assessment may also need to change.

NSW projects

BASIX and NatHERS are connected but not interchangeable

BASIX is completed through the NSW Planning Portal. NatHERS results can be used within the BASIX pathway, but a NatHERS certificate by itself is not the whole BASIX submission.

Confirm the current BASIX settings, plans and certificate requirements for the specific project before construction documents are finalised.

Avoid rework

Ask these questions before modelling starts

Check the source

Current official guidance

Confirm the project pathway before ordering the assessment

Send the location, design stage and current plans. Australian Energy Assessments can complete plan-based NatHERS work anywhere in Australia and BASIX support for NSW projects.

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