Image shows a new home with timber cladding and the text 7 stars Nathers & new homes: what you need to know.

If you’re building a new home in ACT, NSW, VIC, or SA, you’ll need to a 7-Star NatHERS rating and a whole of home assessment. (Yes, QLD too, but we’ll focus on cool climates here.) 

This is a fantastic step forward for building sustainability, but it’s also catching some people off guard. So, what does it actually mean? How hard is it to reach 7 stars? And—most importantly—what can you do to make sure your home is compliant without breaking the bank?

Quick summary of NatHERS 7-Star rating requirements

  • New home builds in ACT, NSW, VIC and SA must reach a minimum 7-star energy rating (in NSW, this is part of new BASIX requirements). 
  • Your design will also need to meet a specific heating and cooling load. 
  • All homes now require a whole-of-home NatHERS assessment. 
  • You have options! Smart design will make all the difference. Read on to for tips below!

Requirement

Old

New

Star rating

6 stars

7 stars

Heating and cooling limits

Yes

Yes – lower

Whole-of-home

Not required

Now required

Note: NSW use their own BASIX system – check out our overview to updated BASIX requirements.

What is a NatHERS rating? (Briefly)

Quick NatHERS refresher: NatHERS (the Nationwide House Energy Rating Scheme) is Australia’s energy efficiency rating system for homes. It calculates heating and cooling demand based on the design, materials, and climate.

It’s not about appliances or solar panels—it’s purely about how well your home holds temperature. (That’s where the Whole-of-Home rating comes in.)

What’s new in the 7-Star rules? 

The minimum rating for new homes goes from 6 to 7 stars

A 6-star NatHERS rating used to be the norm; now you need to achieve a minimum 7-star rating. The new standard was introduced to increase Australian home energy efficiency and comfort, and decrease energy use. This is a good thing! 

The basics remain the same: 

  • The 7-star rating measures heating and cooling energy use only.
  • It still needs to be completed by a licensed NatHERS assessor using accredited software: usually HERO (our favourite), FirstRate5, or Bers Pro.
  • Your design needs to be under the heating load cap and cooling load cap, as well as meeting the star rating limits. 

What’s new: NatHERS Whole-of-Home Certificate

This is NatHERS’ new way of measuring the energy impact of your heating, cooling, hot water system, lighting, and appliances—and how well solar offsets your usage, giving your home a score out of 100.

Where the 7-star rating refers only to your heating and cooling energy use, whole-of-home considers all of your appliances and renewable energy options. You get a score out of 100 for your home. 

You have two compliance options:

  • Whole-of-Home Calculator (detailed assessment).
  • Deemed-To-Satisfy method (faster, easier, limited options).

Our take on Whole-of-Home assessments

We love that operational energy use is finally being considered in NatHERS, but we don’t find this method particularly helpful. We prefer our Monthly Net Zero Score, which actually shows you how your energy bills will behave in real life! 

Nathers 7 star rating certificate showing the star rating, heating and cooling limits and the whole of home rating section.

When is a 7 star energy rating hard to achieve? 

Some home designs sail through compliance. Others? Not so much. If your home has one (or more) of these features, we advise you to get good advice early in your build process.

  • Lots of glass → Glass loses heat fast. Consider double or triple glazing, increase your north-facing windows or reduce overall window amount. 
  • Small homes → Although they are a sustainable choice and use less energy, they can be tricky to rate. Use Performance Solutions for flexibility.
  • High ceilings → High raked ceilings and double voids increase the volume of air, which means more heating and cooling! 
  • Suspended timber floors → A sustainable choice, but NatHERS prefers concrete floors due to the thermal mass. There’s complex science behind it, that we don’t necessarily agree with–use a two stage energy rating process to ensure compliance. 
  • South-facing views → South facing windows loose heat in winter, increasing your heating energy. Offset with window performance upgrades, higher building insulation and/or more north-facing windows to balance the heat loss.
  • Single-glazed windows → No longer feasible in most cold climates unless everything else in your design is performing just right or you live in a goldilocks climate zone that is already comfortable all of the time (looking at you coastal northern NSW). 
  • Steel-framed homes → NatHERS now includes thermal bridging impacts for steel frames, which can lead to moisture and condensation issues in colder climates, creating potential for mould.
Image shows a small tiny home, a bedroom with full glass walls on two sides, a timber floor construction and an artistic picture of a steel frame for a house.
Small homes, houses full of glass and timber floor construction all pose challenges for high NatHERS star ratings.

How to get a 7 star rating home every time?

 Get the solar passive basics right

We want to minimise the amount of heating and cooling your house needs, by maximising free heat from the sun in winter and minimising heat entering the house in summer. If you want a higher energy rating, consider: 

  • Increasing north-facing glass for main living areas = free winter heat!
  • Avoid permanent shading (like a large verandas or covered area) over your north windows. Consider operable or seasonal shading for summer instead.
  • Pay attention to the amount of windows. Glass-to-floor ratios over 35% can be challenging, particularly in colder regions. 
Image shows a north facing window with eave correctly sized to prevent summer sun.
Reaching 7 stars is easier in cool climates when living areas have north-facing windows and no-overshading.

Improve the building envelope

We recommend:

Use a two stage NatHERS rating process

Don’t gamble with your design—check it early!  A two-stage NatHERS rating process is the best way to avoid compliance issues and costly redesigns.

1

Preliminary assessment

Get advice during your design process. Use smart building data to optimise your design for maximum comfort and health, minimal energy bills.

2

Final certification

Secure final compliance once the design is ready for approvals, confident of your star rating, comfort and build choices.

What does this do?

  • Saves money – Avoid costly redesigns and expensive energy efficiency upgrades.
  • Optimises your design – Ensure that this home design is working as hard as it can for comfort, low bills and sustainability.
  • Ensures compliance – No last-minute surprises!

Key takeaways: what you need to remember

  • The new minimum house energy rating requirement is for new homes is 7 stars in NSW, VIC, ACT, SA and QLD.
  • Understanding passive design basics will help you ensure a 7 star outcome.
  • Know if you’ve got tricky design criteria and get advice early.
  • Whole-of-Home assessments (considering energy use, solar panels and battery storage) are also now required. 
  • A two-stage energy rating process together with the Powerhaus home design dashboard helps optimise design and avoid delays.

Let’s get your energy rating sorted!  

Whether you’re an architect, builder, or homeowner, Powerhaus helps you tick the compliance boxes AND design a truly comfortable home.

 We provide:

Start your 7-star journey today—upload your plans for a free quote or contact our team to find out more.

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