The NCC 2022 Change to 7 Stars
The National Construction Code (NCC) 2022 raised the minimum energy efficiency requirement for new residential buildings from 6 stars to 7 stars on the NatHERS scale. This change was introduced by the Australian Building Codes Board (ABCB) to reduce energy consumption in the residential sector, which accounts for approximately 12% of Australia’s total greenhouse gas emissions.
The increase from 6 to 7 stars represents roughly a 20–25% improvement in thermal performance. In practical terms, a 7-star home uses significantly less energy for heating and cooling, resulting in lower electricity and gas bills, improved occupant comfort, and a smaller carbon footprint.
For builders and designers, this means greater attention to insulation levels, glazing performance, building orientation, thermal bridging, and air tightness during the design phase. The good news is that achieving 7 stars is straightforward when energy efficiency is considered early in the design process.
What the 7 Star Minimum Means for Builders
If you are building a new home, the 7-star requirement affects your project in several ways:
- Design stage input is essential — Engaging an accredited assessor during the design phase is the most cost-effective approach. Small changes to orientation, window placement, and insulation specification can make the difference between 6.5 and 7.5 stars without adding significant cost.
- Material specifications matter — Standard construction practices that achieved 6 stars may not reach 7 stars. Builders should expect to specify higher R-value insulation, improved glazing (double glazing is now common), and better air-sealing details.
- Whole-of-home energy budget — NCC 2022 also introduces a whole-of-home energy budget alongside NatHERS, covering fixed appliances like hot water systems, lighting, and pool pumps. This is a new requirement beyond just the thermal envelope.
- Building permit requirement — A NatHERS certificate showing 7 stars or above must be submitted with your building permit application. Without it, your permit will not be approved.
How to Achieve a 7 Star Energy Rating
Reaching 7 stars requires a holistic approach to building design. The accredited consultants in our network regularly help builders and designers meet and exceed the 7-star target. Common strategies include:
- Optimise orientation — North-facing living areas maximise passive solar gain in winter while minimising overheating in summer. This single factor can add 0.5–1.0 stars.
- Upgrade insulation — Ceiling insulation of R5.0+ and wall insulation of R2.5+ are now common requirements. Under-slab or under-floor insulation is also important in cooler climates.
- Improve glazing — Double-glazed windows with low-E coatings are becoming the standard for 7-star homes. Timber or thermally broken aluminium frames perform better than standard aluminium.
- Manage shading — Eaves, pergolas, and external blinds prevent summer overheating while allowing winter sun penetration.
- Reduce thermal bridging — Steel frames conduct more heat than timber. If using steel framing, additional insulation or thermal breaks are needed to compensate.
- Improve air tightness — Sealing gaps around windows, doors, and service penetrations reduces unwanted heat loss and gain.
Cost Impact of the 7 Star Requirement
The Australian Building Codes Board estimates that achieving 7 stars adds between $3,000 and $7,000 to the cost of constructing an average new home. This varies depending on climate zone, building design, and existing specification levels. However, homeowners typically recoup this investment within 5–10 years through reduced energy bills.
The cost of the NatHERS assessment itself ranges from $400 to $1,500 depending on the size and complexity of the home. View our full energy rating cost guide for detailed pricing.
State-by-State Adoption
While the NCC 2022 is a national code, each state and territory adopts it according to their own timeline:
- Victoria — Adopted in full. Victoria has historically been a leader in residential energy efficiency. See our Victoria energy rating guide.
- NSW — Adopted alongside BASIX requirements. NSW homes must meet both 7-star NatHERS and BASIX targets.
- Queensland — Adopted with consideration for tropical climate zones where cooling loads dominate.
- Other states — SA, WA, ACT, Tasmania, and NT have all adopted the NCC 2022 7-star requirement with varying transition timelines.
For a comprehensive overview of the NCC 2022 changes, see our NCC 2022 changes guide.
Get Your Design Assessed
Whether you are at the initial design stage or ready to submit for a building permit, we connect you with accredited NatHERS assessors who can model your home and confirm compliance with the 7-star requirement. Use our Energy Rating Calculator for a preliminary estimate, then request a free quote to be matched with an assessor in your area.
Frequently Asked Questions
What is the 7 star energy rating requirement?
Under the National Construction Code 2022 (NCC 2022), all new residential buildings in Australia must achieve a minimum NatHERS rating of 7 stars. This represents a significant increase from the previous 6-star minimum and reflects Australia's commitment to reducing household energy consumption.
When did the 7 star requirement come into effect?
The NCC 2022 was published in October 2022 with a 12-month transition period. Most states adopted the 7-star requirement by October 2023, though some jurisdictions had their own transition timelines. Check with your local authority for exact dates.
Does the 7 star requirement apply to renovations?
The 7-star minimum applies primarily to new builds. For renovations and extensions, the new work must meet the current NCC requirements, but the existing portion of the building is generally assessed under the standards that applied when it was originally built.
How much extra does a 7 star home cost to build?
Studies by the Australian Building Codes Board estimate that achieving 7 stars adds between $3,000 and $7,000 to the construction cost of an average new home. However, this is offset by ongoing energy savings of approximately $500 to $1,000 per year.
Can I build a home that exceeds 7 stars?
Absolutely. Many homeowners choose to exceed the minimum, aiming for 8 or even 9+ stars for greater comfort and lower running costs. An accredited assessor can model your design and recommend upgrades to reach your target rating.