7-star NatHERS explained: what it means for your new home
The national 7-star energy standard and the Whole-of-Home score in plain English, plus the smartest ways to meet them without over-spending.
Since the National Construction Code 2022 energy updates, a new home almost anywhere in Australia has to meet a minimum 7-star NatHERS thermal rating plus a Whole-of-Home energy score of at least 60 out of 100. Those rules are now standard across SA, Victoria and most other states, and they are set to stay put under NCC 2025, with no further residential energy change expected until around 2029. So it is worth understanding what the numbers mean, because they shape your design decisions from the very start.
What the 7 stars actually measure
NatHERS rates the thermal performance of the shell, how well the walls, roof, windows, insulation and orientation keep the home comfortable before any heating or cooling kicks in. Seven stars is the minimum for a new home. The good news is that the cheapest wins come from design: getting the orientation right, shading the summer sun, insulating properly and placing windows thoughtfully do most of the heavy lifting.
The Whole-of-Home score of 60
On top of the shell rating, the Whole-of-Home assessment looks at the fixed gear in the house, heating and cooling, hot water, lighting and any solar, and scores it out of 100, with 60 the floor. It is a far better guide to real running costs than the star rating on its own, so make a point of getting the final score confirmed in writing before you sign off.
The smart ways to comply
Solar, often paired with a battery, is usually the most effective lever for lifting the Whole-of-Home score, and the federal Cheaper Home Batteries program supports the first 14 kWh of usable capacity. Before you commit to premium double glazing, ask for an early NatHERS assessment. More often than not, better orientation, a bit more shading or a tweak to window placement gets you across the line more easily than upgrading the glass.
The two numbers that matter
- 7-star NatHERS rates the building shell, how well it holds comfort before you switch anything on
- The Whole-of-Home score rates the whole home, including heating, cooling, hot water, lighting and any solar
- Ask for both in writing, because a star rating on its own does not tell the running-cost story
- If the design does not meet them, it cannot be approved
- Chasing stars with pricey glazing when a design tweak would do the job is the classic trap
Treat 7 stars and a Whole-of-Home score of 60 as the floor, not the finish line, and make the design earn its rating before you buy your way there. The single best move is an early NatHERS assessment, because it tells you whether to adjust the design, add solar, or spend on glazing, rather than guessing.
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What does a 7-star NatHERS rating mean?
It is the minimum thermal rating for a new Australian home. NatHERS scores how well the building shell, the walls, roof, windows, insulation and orientation, keeps the home comfortable without heating or cooling. Seven stars is now the national minimum.
What is the Whole-of-Home score of 60?
It is a separate score out of 100 that covers the whole home, including heating, cooling, hot water, lighting and any solar. New homes must reach at least 60, and it reflects running costs better than the star rating alone.
Do I need double glazing to reach 7 stars?
Not always. It helps in some climate zones, but better orientation, shading and window placement can get you there more easily. Ask for an early NatHERS assessment before committing to expensive glazing.
What is the easiest way to meet the energy rules?
Start with design, orientation, shading, insulation and sensible windows. Then solar, often with a battery, is usually the most effective lever for the Whole-of-Home score, helped along by the Cheaper Home Batteries program.