The Building Sustainability Index (BASIX) aims to deliver equitable, effective water and greenhouse gas reductions across the state. BASIX is one of the strongest sustainable planning measures to be undertaken in Australia.

BASIX and the planning system

An integrated part of the planning system, BASIX is implemented under the Environmental Planning and Assessment Act. BASIX applies to all residential dwelling types and is part of the development application process in NSW.

BASIX assessment

BASIX is assessed online using the BASIX assessment tool. The tool checks elements of a proposed design against sustainability targets.


BASIX reduces water and energy consumption in homes across NSW. These environmental outcomes also provide a long term financial saving for the homeowner – and a valuable contribution to the sustainable future of our communities. 



Introduced on 1 July 2004, BASIX is an integrated part of the NSW planning system. It has reduced potable water consumption and greenhouse gas emissions for new homes built in NSW and won numerous awards.

timeline icon2004 

BASIX commences in Sydney Metroploitan LGAs: New single dwellings and dual occupancy; New boarding houses, guest houses, hostels, lodging-houses and backpacker accommodation under 300m2.

 timeline icon2005

BASIX expands to all NSW: New single dwellings and dual occupancy; New boarding houses, guest houses, hostels, lodging-houses and backpacker accommodation under 300m2.


 timeline icon2005oct BASIX expands to also include villas, townhouses and residential flat buildings in NSW.


 timeline icon2006

3 energy target zones introduced for single dwellings of 25%, 35% and 40% reduction in greenhouse gas emissions.

 timeline icon2006oct

BASIX expanded to apply to: residential alterations and additions throughout NSW, with a total cost of works $100,000 or more.

 timeline icon2007

Threshold for alterations and additions subject to BASIX changed to a total estimated cost of works of $50,000 or more.

 timeline icon2009

BASIX thermal comfort section realigned to NatHERS 2nd Generation software.

 timeline icon2010

Better Regulation Office recommends a five year review. Completed Review is submitted to IPART which recommends revision of BASIX targets.

 timeline icon2011

Fee introduced for BASIX Certificate (New Homes)

 timeline icon2011Nov Fee introduced for BASIX Certificate (Alterations and Additions)
 timeline icon2017 Energy targets increased. Thermal comfort stringency for heating and cooling increased.



BASIX has received several industry and government awards. In 2004 BASIX won Gold in the Environment category at the Premier's Public Sector Awards. The following year it won the Australian Property Institute's Kemp Strang Property Industry Award and the Planning Institute of Australia's National Urban Planning Achievement Award. 2007 saw BASIX win an Australian Institute of Energy award for "Energy in Society - For contributing to policy, law and the community".

In 2011, members of the BASIX delivery team where finalists in the NSW Premiers Awards for the publication of the BASIX Five Year Performance Report and received an award for “Best Application Paper” for a peer reviewed paper and presentation to the IBPSA 2011 International Building Simulation Conference.