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New BASIX Changes

Think New Build Prices will drop> Think Again.

Major Legislative Changes about to cost you 10’s of Thousands.

NSW Government has committed an achievement of net zero emissions by 2050. This promise has led to a dramatic increase in the BASIX standards for energy use and thermal performance for all new home builds in New South Wales. From October 1st, the Government will begin it’s push to be “Net Zero” by 2050. Meaning, from that date, all new home builds will be required to reduce carbon emissions. Whilst this is good for our environment long term, and we support the target, it will mean the cost to build a home will rise substantially, effective immediately from October 1.

So, what exactly is BASIX?

If you are new to building, BASIX (known as the Building Sustainability Index) is a development standard that applies across all new builds in NSW. BASIX sets sustainability targets for water and energy, as well as minimum performance levels for the thermal comfort of your proposed home. It can be a complex balancing act taking into consideration your block, and your design, to formulate the best way to achieve the standard for certification.

As a requirement of your new build, we must submit a BASIX Certificate to show we have met or exceeded these requirements before we are permitted to commence your build. This BASIX certificate is a requirement whether you are building under a CDC or DA.

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But how does the new BASIX change affect my build?

There is a relatively large “unknown” factor at this stage as this will vary depending on your specific design proposed on your land. Frys Energy Wise – an independent BASIX assessor who works with ANSA Homes, determines the following will become the new bare minimum requirements.

Managing Director, Ian Fry says, “There are a lot of changes coming on October 1, but the key ones to note for a standard new home build in Sydney are:

  • External Wall Insulation – R2.5 minimum
  • Roof Insulation – R6.0 minimum
  • Use of light roof colours as much as possible
  • Single storey home designs to have Low E to bedroom windows and Double Glazed to living room windows.
  • Double storey homes to have double glazing to all windows except wet areas.

What are the real cost implications?

We all know that no home is the same, so depending on your location, block aspect and home design your extra BASIX costs may vary. An initial assessment of the increased costs will look like this:

Minimum price rise diagram

The below diagram represents a minimum cost you will incur after the BASIX changes are implemented. Costs will change depending on your ceiling height, window size and amount of windows.


To help you understand the implications we have designed the case study above based on our Seabrook Home – on display at Box Hill, using our current Elevate Collection Inclusions. Overall the increase is from 3 – 6% of your total build cost.

You may forgo your design vision

Another issue with the new BASIX regulations is the impact on the actual design of your facade. If you are looking for a highly architectural style home – perhaps with a lot of windows to capture an extraordinary view you might find that after October 1 your vision will need to be drastically altered to achieve your dream and in fact your original design may never pass the new rules.

But aren’t housing prices falling?

Mark Maloney, Director ANSA Homes says, “There is a lot of talk about the prices of houses coming down for the existing home market but that’s just not the case for the new build market. As history reflects, costs for materials across the industry continue to rise, and will always track in that direction, meaning builders have no choice but to pass this on to the client.”  

The bottom line is, waiting for prices to fall is not a sound strategy.

When do I need to act?

If maintaining your budget and keeping your inclusions and design vision intact is an important factor for you, then you need to make sure your CDC or DA is lodged with a valid BASIX Certificate before the new Legislation takes effect on October 1. However, this doesn’t mean you have the time to wait until September to act. The new build process is quite complicated as shown in the below diagram and you need to have started the process with ANSA Homes by no later than June 1, 2023, to ensure your lodgement is accepted by council before the cut-off time. That being said council will likely be overwhelmed with lodgements and that will extend the time further. If you want to build – it’s a good idea to start the conversation very soon with your builder.

What will happen if I miss the deadline?  

Things aren’t all bad if you miss the deadline. There are many energy saving areas that a builder can use to meet your BASIX requirements and still keep your tender price low. These might include:

  • Reduction in window size
  • Reduction in ceiling height
  • Reduction in slider door height
  • Add eaves over modern façade windows

However, we think it’s important to make you aware of this as it will affect the design outcome for your new home build – leaving you with a home which may not meet your vision. Other things you will need to consider include are:

  • Land Aspect
  • Position of Windows
  • Step downs in the Home
  • Ceiling Heights
  • Facade Design
  • Size of Eaves
  • Position of Alfresco

This will be a challenge for many home building companies, which is why it’s important to talk to an ANSA Homes compliance and design expert to understand the implication of these upcoming changes on your new home build.