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BASIX aims to create more comfortable and cost-efficient homes


The Building Sustainability Index (BASIX) requirements 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 requirements for water and energy usage and thermal comfort 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 plans meets the BASIX requirements.

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.

*savings up to 30 June 2021.

A snapshot of NSW insights

The information captured in the BASIX system provides a rich source of data insights about the choices people make in residential development, such as the average number of bedrooms in new dwellings, the type of kitchen appliances chosen (gas or electric) and the types of cooling systems used.

Download the Annual Snapshot for 2017/18

Download BASIX Certificate data (from 2011/12 to 2017/18) 

An overview of the assessment process

To demonstrate your development meets the BASIX requirements, you must conduct an assessment using the online BASIX Tool, which estimates the water and energy consumption and the thermal comfort based on the information you provide. This information includes the floor area, the size, location and type of windows, the type of insulation and the type of hot water system being installed.

There are detailed help notes available on the BASIX website to guide you through the process.

Once you have successfully completed the assessment by meeting the BASIX targets, 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: 16/08/2022