Question 1

What is a 7 star energy rating?

Accepted Answer

A 7 star energy rating is the minimum NatHERS thermal performance standard required for all new residential builds in Australia under the National Construction Code 2022 (NCC 2022). It means the home is modelled to use roughly 24% less heating and cooling energy than the previous 6-star minimum. Every new house, townhouse, and apartment that lodges a building permit after the NCC 2022 commencement date must achieve 7 stars or above on the 0–10 NatHERS scale.

Question 2

Is 7 stars mandatory for new homes?

Accepted Answer

Yes. Since NCC 2022 took effect (1 May 2023 in most states, with NSW and WA on transition timelines), 7 stars is the minimum legal NatHERS rating for new Class 1 (houses) and Class 2 (apartments) builds nationally. The rating must be issued by a NatHERS-accredited assessor and lodged with the building permit.

Question 3

How much extra does building to 7 stars cost?

Accepted Answer

Industry estimates put the additional build cost at roughly 0.5%–3% over a 6-star spec — typically $3,000–$15,000 on a standard house — usually recovered in 5–10 years through lower heating and cooling bills. The biggest cost drivers are upgraded glazing (double-glazed or low-E), continuous wall and ceiling insulation, and improved air-tightness detailing.

Question 4

How is a 7 star rating achieved?

Accepted Answer

Achieving 7 stars usually involves: correct orientation with living areas facing north, well-sized eaves and external shading, R4.0+ ceiling insulation, R2.5+ wall insulation, double-glazed or low-E windows on west and east elevations, draught sealing around doors and exhaust fans, and considered floor coverings. An accredited assessor models these choices in AccuRate, FirstRate5, or BERS Pro and iterates until the design reaches 7 stars.

Question 5

Will 7 stars become 8 stars?

Accepted Answer

The Australian Building Codes Board has signalled an intended progression toward higher minimums in future NCC updates, with industry discussion centred on 8 stars in the 2030s — but no nationally mandated date has been set. For now, 7 stars is the legal minimum and 8+ stars is voluntary best-practice common in high-performance and Passive House-inspired builds.

Rating	Typical home	Heating + cooling load
3 stars	Average existing Australian home	Very high — expensive bills
6 stars	Pre-2022 new build (old minimum)	Moderate
7 stars	NCC 2022 new build (legal minimum)	~24% lower than 6 stars
8 stars	High-performance build	Significantly lower bills
9–10 stars	Passive-house style	Barely any active heating/cooling

7 Star Energy Rating — Australia's NCC 2022 Minimum, Explained

Where 7 stars sits on the NatHERS scale

How to design for 7 stars

What it costs

Book a NatHERS assessor for your 7-star design

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