Blog

WA’s shift to 7-star efficiency ratings

What is a 7-Star energy rated home and why are the guides changing

If you’ve recently built a home in Australia or have been looking to build it is likely that you’re familiar with the energy efficiency ratings that your new home has to be built to. In Australia, the National Construction Code (NCC) stipulates that all newly built homes have a minimum 6-star energy rating across all of the built features. But did you know the NatHERS energy rating scale actually goes up to 10?

There has been a big push recently across Australia to increase the minimum efficiency ratings from a 6 to a 7 and for the assessment to include the entire house; shifting the requirements to include things like appliances and services. This change is quite a significant and a lot more work will be required to go into the design phase to ensure the homes complies across all aspects.

What do the stars represent?

The NatHERS star rating system represents how insulated the home is from the external temperature. A 10-star home (the highest possible rating) is able to maintain a comfortable temperature inside regardless of the temperature outside – meaning it has to consume less energy to make internal adjustments.

According to experts, a jump from 6-stars to 7-stars could mean a home is only uncomfortable for a number of weeks each year rather than a number of months.

So why the efficiency ratings push?

There are a number of reasons for the efficiency ratings jump from a minimum 6-star rating to a 7-star rating. From a legislative standpoint it all started in 2019 when the Trajectory for Low Energy Buildings was agreed by all Commonwealth, state and territory energy ministers. This initiative aims to achieve zero energy and carbon-ready commercial and residential buildings in Australia. Shifting to a 7-star minimum NatHERS rating is an important step as part of this commitment to:

• lower energy bills
• contribute to energy security and affordability
• reduce carbon emissions
• improve people’s comfort and health
• reduce wastage for the wider economy
• assist in lowering peak demand

In fact experts believe an efficiency ratings jump from a minimum 6-star rating to a 7-star rating will reduce energy costs for the home owner by up to 20%!

How do you achieve it?

Achieving a 7-star energy rating can seem like a big leap but in actuality it is a fairly straightforward process that needs to be undertaken at the design phase.

To reduce the reliance on energy cooling/heating devices, things like the homes orientation are critically important. Designers are pushing the boundaries more and more to ensure that a home is designed to maximise the natural orientation and building envelope to conserve energy usage. It is likely you will see a significant change in off-the-plan home designs when the 7-star efficiency ratings requirements come into effect.

Different building materials will also be essential to achieving a 7-star rating and materials that provide higher thermal mass and insulation will be essential. This could be part of the interior (eg internal wall composition) or simple things like roof colour and materials.

Whole-of-home assessment

A shift is also underway to ensure your entire home is compliant with the energy rating, and along with an assessment of the thermal qualities of the home, you will also have to ensure you provide information about:

• cooking appliances
• heating and cooling appliances
• hot water services
• lighting
• pool/spa pumps and equipment
• solar panels

These items are taken into consideration now as part of the whole-of-home certification so it is important to consider these choices when you are moving towards the build stage of your home.

Will higher efficiency ratings cost me more?

Complying with a jump from a 6-star rating to a 7-star rating doesn’t have to come with any additional or surprising costs if planning for certification is done at the design stage. Working closely with a designer to design your home specifically for your block is essential.

Over the last few years it is safe to say that we have spent more time in our homes than ever before, and with many of us still working from home or practicing flexible working arrangements our homes and the energy they consume have become a hot topic for discussion. It is more important than ever to ensure the built Australian landscape is contributing and pioneering the evolution to an energy neutral environment and this shift is just the beginning.

We encourage all homeowners to not look at the shift as restrictive and costly, but as an opportunity – an opportunity for progressive design and cost savings in the long run.

If you would like to know more about WA’s shift to 7-Star efficiency ratings, contact us today: https://www.designerhomeextensions.com.au/contact