Building Sustainability Index (BASIX)

Building Sustainability Index (BASIX) ensures that homes are built to be more energy and water efficient by setting clear sustainable housing targets for new homes developed in NSW. The aim of this is to reduce greenhouse gas omissions and set water reduction targets. It is a requirement of the NSW Government that all new housing developments submit a BASIX certificate, and it should be submitted to your local Council in the design phase of development.

The BASIX online tool is simple to use and can be either by yourself or your builder. Data about your new house or unit is input into the tool and then BASIX analyses the data to determine how it scores against energy and water targets. The design must pass specific targets before a certificate will be granted.

Since the implementation of this initiative, the Department has been monitoring 100 BASIX compliant homes. Of these houses, when it comes to rainwater tanks, they have noted that every home has a rainwater tank, with the average size being 4000 litres and the majority of which will be plumbed to the toilet and laundry, as well as providing water for the garden.

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building sustainability index - Sydney Water Tanks