NatHERS 7-Star Rating and the NCC: What It Means for Your Windows

Key Takeaways

• New homes in Victoria must now meet the 7-star NatHERS energy rating under NCC 2022, which has been mandatory in Victoria since 1 May 2024.
• The ACT adopted the same 7-star and whole-of-home requirements from 15 January 2024.
• NCC 2025 took effect in Victoria on 1 May 2026, but it did not raise residential energy efficiency requirements, so 7-star remains the standard.
• Windows are one of the biggest levers for reaching 7 stars, because glass and frames affect heating and cooling loads directly.

What the NCC 7-Star Rating Means

The National Construction Code (NCC) sets minimum standards for how new buildings are designed and built in Australia. For homes, one important measure is the NatHERS star rating, which estimates how much energy a home needs to stay comfortable.

The scale runs from 0 to 10 stars, and more stars means a home needs less heating and cooling. According to Sustainability Victoria, a 7-star home needs around 20 to 25% less heating and cooling energy than a 6-star home in most locations.

• NatHERS: the Nationwide House Energy Rating Scheme, which rates the design of a home using accredited software.
• Star rating: a score out of 10 for the building’s thermal performance.
• Whole-of-Home: a separate requirement that looks at the energy use of equipment such as hot water and heating and cooling systems.

You can find an overview of the scheme on the NatHERS website.

Key Dates for Victoria and the ACT

The timeline matters if you are planning a build, because the rules that apply depend on the date of your building permit and your location. This summary covers the main steps.

The Victorian Government publishes the official detail, so check Victorian Government building standards before you finalise plans.

What Changed With NCC 2025?

Many builders asked whether NCC 2025 would raise the bar again. For residential energy efficiency, it did not.

The 7-star standard from NCC 2022 carries forward, and industry bodies report that further changes to residential energy efficiency requirements are paused until about mid-2029. That gives designers and homeowners a stable target to plan around when selecting windows and doors.

• No new star increase: 7-star remains the minimum rating for new homes.
• Stable window targets: performance values used in your energy assessment are unlikely to tighten soon.
• Other changes exist: NCC 2025 updated other areas, so your builder should confirm what applies to your project.

Why Windows Matter for a 7-Star Home

Windows and glazed doors are usually the weakest part of a building’s thermal envelope. Heat flows through glass and frames far more easily than through an insulated wall, so window choices have a large effect on a star rating.

Assessors enter each window’s performance into the energy model, so the specification you choose can raise or lower the final result.

• Frame material: uPVC insulates better than standard aluminium and helps limit heat flow through the frame.
• Glazing type: double glazing, Low-E coatings and argon gas cut heat transfer across the glass.
• Window size and position: large west-facing windows add summer heat, while north-facing glass can help in winter.
• Air sealing: compression seals reduce draughts that waste heating and cooling.
• Window ratings: a WERS rating gives a standard way to compare products.

Our guide to energy efficiency windows explains these values in more detail.

Windows That Help You Reach 7 Stars

Ultimate Windows manufactures uPVC windows and doors in Wodonga, Victoria. Our uPVC is up to 4.5 times more energy efficient than standard aluminium-framed windows, and argon gas is included as standard at no extra cost.

Options that support a 7-star design include:

• Double glazing with Low-E glass: a standard choice for most new builds and renovations.
• Triple glazing: for higher performance targets or cold sites.
• Warm edge spacers: non-metal spacers that reduce heat loss at the glass edge.
• Passive House certified Legend system: for projects aiming well beyond the minimum.

Learn more about glass that meets energy ratings to see how coatings and gas fills affect performance.

Planning Tips for Builders and Homeowners

Getting windows right early avoids costly changes after your energy assessment. Follow these steps to keep your project on track.

1. Confirm which edition of the NCC applies to your building permit with your builder or surveyor.
2. Share your window schedule with your energy assessor before lodging plans.
3. Ask suppliers for U-values and SHGC figures, or a WERS rating, for each window type.
4. Test different glazing options in the model to see their effect on the star rating.
5. Order windows made to measure once openings are finalised.
6. Use an installer who seals the frame carefully to maintain airtightness.

If you build in the ACT or near the border, our page on double glazed windows in Canberra covers local service.

Common Window Mistakes in Energy-Rated Builds

Many projects lose stars because of avoidable window decisions made late. These are the problems we see most often when people plan a new home or major renovation.

• Choosing windows after the energy report: a swap to a weaker product can change the rating.
• Ignoring orientation: big west-facing glass raises summer cooling loads.
• Relying on frame colour or style alone: performance comes from the tested specification.
• Skipping shading: eaves and shading help the glass work harder for you.
• Poor installation: gaps around the frame undo the benefit of good glazing.
• Not asking for data: request tested figures so your assessor can model the real product.

Frequently Asked Questions

What is a 7-star energy rating?

A 7-star energy rating means a home meets a high level of thermal performance on the NatHERS scale, which runs from 0 to 10. It indicates the building needs less heating and cooling to stay comfortable, based on design, materials, orientation and windows.

When did 7-star become mandatory in Victoria?

The NCC 2022 energy efficiency requirements, including 7-star NatHERS and the whole-of-home requirement, became mandatory in Victoria on 1 May 2024. The ACT introduced equivalent requirements earlier, from 15 January 2024, so check which rules apply to your project and permit date.

Did NCC 2025 increase the star rating requirement?

No. NCC 2025 became mandatory in Victoria on 1 May 2026, but it did not add new residential energy efficiency stringency, so the 7-star requirement continues. Further changes to residential energy efficiency are reported to be paused until around 2029.

Do double glazed windows help meet a 7-star rating?

Yes. Double glazing lowers heat transfer through the glass, and uPVC frames insulate better than standard aluminium. Together they reduce heating and cooling loads in the energy model. The final result still depends on window size, orientation and the rest of the design.

Choose Windows That Support Your 7-Star Build

The right windows make it easier to hit your energy target without compromising your design. Our team can help you compare options, supply performance figures and give you a free measure and fixed-price quote. Call 1300 898 782 to speak with us.