Using the BASIX assessment tool

How the assessment tool works

Based on the data you provide regarding your building design, the BASIX tool assesses the anticipated water consumption and greenhouse gas emissions levels of your proposed development. The expected thermal performance of the proposed building is also assessed as part of BASIX. For the water and energy targets, the development is assessed on how it is likely to perform against existing dwellings of the same type.

Comprehensive data sets

BASIX uses comprehensive data sets supplied from utility organisations, state agencies and the Australian Bureau of Statistics to analyse and compare your proposed development against the NSW 'average'. This data includes resource demand, occupation levels, and market penetration rates of technology, climate and other factors.

An ongoing comprehensive analysis of sustainable technology ensures that BASIX is contemporary and reflects best practice in sustainable housing.


Algorithms within the BASIX tool calculate how your single dwelling, alteration and addition or multi-unit is likely to perform against a benchmark development of the same type.

Users are guided through the assessment process step-by-step. Diagrams and help notes are available throughout the tool to help users should they need clarification.

Using the BASIX assessment tool

In order to obtain a BASIX certificate for your proposed development, you will need to complete our sustainability assessment using the BASIX assessment tool.

How the assessment tool works

The BASIX assessment tool analyses data relating to the design of your proposed dwelling and determines how this scores against water and energy targets. The dwelling design must meet specific targets before the proposed development can be issued with a BASIX certificate.

Once the design complies with BASIX, a BASIX certificate listing the sustainability commitments can be printed and submitted with the development application.

Where can I access the tool?

You can access the BASIX assessment tool on this website - both on the BASIX homepage and the right hand column of all pages.

If you have already registered you should be able to log-in straight away using your username and password. If you are new to BASIX you will need to create an account: