Residential sustainability · NSW
BASIX & NatHERS. Better-informed design.
Residential sustainability and thermal performance assessment support in NSW, helping project teams work through BASIX requirements, NatHERS modelling and practical design choices.
The approach
BASIX and NatHERS explained
BASIX (Building Sustainability Index) is the NSW sustainability assessment framework applying to many residential development proposals. Its standards address water use, energy use and thermal performance. Where a BASIX Certificate is required, the commitments must be reflected in the relevant project documents.
NatHERS (Nationwide House Energy Rating Scheme) is a method for assessing the thermal performance of residential design through accredited software and, where relevant, a whole-of-home energy assessment. A NatHERS assessment may support the thermal comfort component of BASIX; it does not automatically replace the BASIX process.
Our services
Our residential energy services
BASIX assessment
Review proposed dwelling details and relevant sustainability measures, and prepare or coordinate the BASIX assessment and certificate as agreed.
NatHERS and thermal performance
Assess heating and cooling performance using an appropriate thermal simulation pathway where required and included in scope.
Design refinement
Provide practical feedback on orientation, glazing, shading, insulation and design choices that may influence performance.
Documentation coordination
Help align nominated BASIX commitments and assessment assumptions with the design documentation for the relevant stage.
Project outcomes
When should energy assessment start?
It is best to consider sustainability requirements while the design can still respond to them. Window sizes, glazing specification, insulation, shading and building services all influence the options available.
Not every project requires both a separate NatHERS assessment and BASIX. The appropriate assessment method depends on the type of work, applicable requirements and agreed service scope.
How it works
From enquiry to clear advice.
A practical process suited to the stage and complexity of your project.
Confirm the assessment pathway
Identify which BASIX and thermal performance requirements apply to the proposal.
Review inputs and model where needed
Assess supplied design details and undertake or coordinate the relevant assessments.
Finalise commitments
Discuss any design refinements and issue the agreed assessment documentation.
Common questions
Good questions to ask early.
Does every project need a BASIX Certificate?
No. BASIX applies to specified categories of NSW residential development, including new dwellings and certain alterations, additions, pools and spas. Applicability should be checked for the particular proposal.
Does a NatHERS rating replace BASIX?
No. NatHERS may inform an eligible thermal performance assessment, while BASIX also deals with water, energy and other required commitments.
Can we improve thermal performance before the plans are final?
Yes. Early advice about orientation, glazing, shading and insulation can help the design team consider improvements before detailed specifications are locked in.
Further information from official NSW Government sources:
Start here
Ready to discuss your project?
Send us the basics. If you already have a survey, plans, sketches or supporting documents, include them too.