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Learn about BASIX, how it applies to your development and how it is helping our environment.


The Building Sustainability Index (BASIX) standards apply to all residential dwelling types and are part of the development application process in NSW. BASIX is one of the strongest sustainable planning measures to be undertaken in Australia.

In NSW, there are BASIX standards for water and energy usage and thermal performance that apply to:

  • all new residential dwellings.
  • alterations and additions to dwellings that cost $50,000 or more.
  • swimming pools of 40,000 litres or more.

To approve such developments, the consent authority (usually your local council) requires evidence that the development plan meets the BASIX standards.

Since 2004, more than 500,000 BASIX-compliant homes are estimated to have saved 12.3 million tonnes of greenhouse gas emissions, and 340 billion litres of drinking water.

An overview of the assessment process

To demonstrate your development meets the BASIX standards, you must conduct an assessment using the BASIX tool, which estimates the water and energy consumption, thermal performance and the embodied emissions of the building materials based on the information you provide. This information includes the floor area; the size, location and type of windows; type of insulation and type of hot water system being installed.

There are detailed help notes available on the BASIX website to guide you through the process. You can read our help notes for energy, water, thermal performance and the materials index.

Once you have successfully completed the assessment by meeting the BASIX standards, you must generate a BASIX certificate and submit it with your development application or complying development certificate. The BASIX certificate lists the key elements of the design, which are referred to as sustainability commitments.

Last updated: 06/05/2024