BASIX - Building Sustainability Index

BASIX Certificate requirements

BASIX is a mandatory certificate under the Environmental Planning and Assessment Act applying to most residential development approvals in NSW. 

BASIX will ask you for information about your proposed development, such as site location, dwelling size, floor area, landscaped area and services and compares the proposal to the average of existing housing.  The proposal is scored according to its potential to consume less potable water or energy than the average existing dwelling.

Applications for BASIX affected development must be accompanied by a BASIX certificate before they can be assessed and development consent granted. Assessments are prepared using the BASIX assessment tool.

BASIX online assessment

BASIX is assessed online using the BASIX assessment tool and aims to reduce water and energy consumption in homes across NSW.  These environmental outcomes also provide a long term financial saving for the homeowner. 

Development that needs a BASIX certificate

Every application for development consent or a complying development certificate for a new residential development (including granny flats) must be lodged with a BASIX certificate.

A BASIX certificate is needed for residential alterations and additions that cost $50,000 or more. A certificate is also needed for swimming pools with a volume of more than 40,000 litres.

If your development requires a BASIX certificate then you must include the BASIX certificate with the development application that is lodged with council.  All specific commitments that the BASIX certificate requires to be shown on the development application plans must be shown on development application plans.  For example, if the certificate states that a 4,500 litre rainwater tank is needed, the plans must show a 4,500 litre rainwater tank.

Exemptions from a BASIX certificate

Alterations and additions that are valued at less than $50,000 are exempt from the need for a BASIX certificate.  Minor developments, including garages, storerooms, car ports, gazebos, verandahs and awnings are exempt.

Conversion of an existing structure (such as a garage) to a granny flat is not exempt from BASIX, even if its value is less than $50 000.

You may voluntarily lodge a BASIX certificate for a project that would normally be exempt.


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