BASIX assessment support for NSW residential projects
Building or renovating in NSW? BASIX is part of the planning process. It checks water, energy, thermal performance and materials for the project. The BASIX certificate and commitments need to match the plans you submit for approval.
Official guidance reviewed 1 September 2026BASIX rules, tools and eligible thermal methods can change. Confirm the current requirements in the NSW Planning Portal and with the relevant consent authority.
New South Wales service areaBASIX is a New South Wales planning pathway. Project eligibility, service availability and timing are confirmed before assessment work begins.
What BASIX covers
The project, the assessment method and the commitments
NSW planning pathway
Confirm whether BASIX applies
BASIX is part of the NSW planning system for applicable residential development. The project type, scope and approval pathway determine the current assessment requirements.
Check the project, not a generic rule
The NSW Planning Portal and the relevant consent authority remain the source of truth for whether a BASIX certificate is required and what it must cover.
Start with
NSW project address
Development type and proposed work
Approval stage and consent authority
Current Planning Portal project details
Pathway result
A confirmed BASIX scope before detailed water, energy, thermal performance and materials or embodied emissions information is entered or relied on.
The BASIX assessment records project commitments that need to remain consistent with the design information and approval documents used for the development.
Changes can affect the certificate
A later change to the design, materials, fixtures or fixed systems may require the BASIX assessment and related documents to be reviewed before approval or construction proceeds.
Control together
Water fixtures and landscape information
Thermal construction and glazing
Fixed energy systems
Materials and current plan revisions
Project use
A BASIX certificate and commitments that describe the same project as the drawings and specifications submitted through the confirmed NSW approval pathway.
No. BASIX is a NSW planning assessment covering several sustainability areas. A NatHERS simulation can be the thermal performance method used within an eligible BASIX pathway, but it does not replace the broader BASIX assessment and commitments.
Does every NSW renovation need a BASIX certificate?
Not every project follows the same rule. The development type, scope, current NSW requirements and consent pathway determine whether BASIX applies. Confirm the project in the NSW Planning Portal or with the relevant consent authority.
Can the BASIX certificate use different details from the plans?
The certificate commitments and submitted plans need to describe the same project. Conflicting construction, glazing, fixture, appliance or system information should be resolved before the documents are relied on for approval or construction.
What happens if the design changes after assessment?
Review the effect of the change on the BASIX inputs, commitments, certificate and approval documents. The consent authority or Planning Portal pathway determines whether updated evidence is required.
Need help with BASIX?
Tell us what you are building or renovating
Start with the NSW address, project type, approval stage and current plans. We will explain the likely pathway and what information is needed next.
