Knockdown and rebuild: Sustainability requirements

01 Feb 12 07:00AM EST
Post by Corinna Horrigan

While we were looking at display homes before beginning our build, we often heard BASIX mentioned – though we had no idea what it was at the time. We eventually discovered that it related to the NSW government regulations regarding sustainability.

We were concerned about the environmental and anticipated increases in energy costs so we were certainly interested in optimising the sustainability of our new house - and we were happy for some help.

BASIX (Building Sustainability Index) is the NSW system of assessing the sustainability of a dwelling in three areas:

  • Water
  • Thermal comfort
  • Energy
You need to get a BASIX certificate before you can submit your development application to the council.

While BASIX is a NSW regulation, most states have regulations that cover at least the energy sustainability of the house. (See the links below for more info in your state or territory.)

To get a BASIX certificate you, or the designer or architect, submit details regarding the proposed dwelling to the BASIX site using a form available online. The information includes things such as location, building materials, orientation and so on. The details are scored in the three different areas and your house has to meet targets in each of them. If the house as submitted doesn't meet any one of those targets, then various things may have to change or be added. The website gives information on what kinds of things will increase the score in each section.

Most of the builders we spoke to included about $10,000 in the quote for meeting the requirements. If it costs less than $10,000, you won't be charged (so make sure all costs are detailed) but if your house has problems, you may find it costs more. In our case, it came to just under the $10,000 – but not by much.

What sorts of things were required?

In our case the requirements included a minimum size for the rainwater tank (6,000 L) and a permanent external clothesline. The water tank had to be plumbed so that it could supply the toilets and the laundry. These were all things that we would likely have done anyway and the cost came in at just under the $10,000 allowance so that was an added bonus.

Of course, we had had some environmental considerations in mind when we were planning the house. All the north facing windows helped with our assessment, as did the eaves and the gas hot water. Finances prevented us from doing all that we would have liked straight away, but we do have plans for solar cells on our nicely angled and north facing roof.

The assessment of the energy rating of a building has to be done by accredited assessors using accredited methods and software. The framework for this is provided by NatHERS (Nationwide House Energy Rating Scheme) which gives consistency in energy ratings throughout Australia.

State and territory sustainability links

Have you had any experience with BASIX or other sustainability regulations when building a new house? Did you find the requirements easy to understand and meet?

Previous Knockdown and Rebuild posts:

Next post, Corinna will talk about submitting the Development Application to council.

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