Project Guidance
A 7 Star Energy Rating can influence the way a residential project is designed, documented and assessed. For many new homes, it means thermal performance needs to be considered earlier rather than treated as a final compliance check.
In brief: A 7 Star Energy Rating usually refers to a 7 Star NatHERS thermal performance rating for a new home. For project teams, the key impact is practical: orientation, glazing, shading, insulation, roof colour, construction details and documentation can all affect whether the project reaches the required outcome without late redesign.
A 7 Star NatHERS rating is not just a number on a certificate. It reflects how well the proposed home is expected to perform thermally in its location and climate. The assessment looks at how much heating and cooling the home may need to maintain comfortable indoor conditions across the year.
For a project, this means the rating can affect design decisions before construction. A home that is well oriented, appropriately glazed, properly shaded and carefully insulated is usually easier to assess than a design that relies on late-stage specification upgrades to solve performance problems.
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Learn what the 7 Star NatHERS requirement means for new residential projects.
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Under a higher-performance NatHERS context, design decisions that may once have been adjusted late in documentation can become more important earlier in the process. Large areas of unshaded glazing, poor orientation, weak insulation or unresolved construction details can make it harder for the dwelling to reach the required rating.
For designers and builders, this usually means paying closer attention to:
A NatHERS assessment is most useful when it can still inform the design. If the assessment is left until the end, the available changes may be limited to more expensive glazing, added insulation or other specification adjustments. Sometimes those changes are enough. Sometimes the issue is more fundamental.
Early review can help identify whether the design is generally on track or whether certain parts of the home are likely to create rating pressure. This gives the project team more room to respond before drawings, costs and approvals become harder to change.
A 7 Star rating is not determined by one product or one design feature. The result usually depends on how the whole home performs as a system. A high-performing window may not solve poor orientation. More insulation may not fully offset excessive unshaded glazing. A lighter roof colour may help in some climates but is not a substitute for a well-considered building fabric.
Common issues that can affect the outcome include:
The 7 Star NatHERS rating focuses on the thermal performance of the building fabric. It models how the home responds to heat, cold, sun, shade and local climate conditions. It does not directly measure the way future occupants use the home.
Whole of Home energy performance is different. It considers major fixed appliances and energy systems such as hot water, heating and cooling equipment, solar and batteries. For many new homes, both the NatHERS thermal rating and Whole of Home result need to be considered as part of the residential energy compliance pathway.
The clearer the documentation, the easier it is to assess the project accurately. A NatHERS assessor will usually need enough information to understand the design, construction systems, insulation, glazing, shading and site conditions.
Useful documents may include:
If the documentation is not complete, an early review can still be useful. It may help identify missing information or flag the design elements most likely to influence the final NatHERS outcome.
The best time to involve a NatHERS assessor is before the design is fully locked in. At this stage, there is usually more flexibility to adjust glazing, shading, insulation, roof colour or construction details without creating unnecessary redesign pressure.
For simple projects, assessment may be straightforward once the documentation is ready. For more complex homes, early advice can help the project team understand the likely pathway and reduce the risk of unexpected compliance issues later.
Certified Energy can review your residential project documents and advise whether NatHERS, BASIX, Whole of Home or another residential energy compliance pathway applies.
It means the proposed home needs to achieve a strong thermal performance outcome under NatHERS. In practice, this can affect glazing, shading, insulation, orientation, roof colour, construction details and the timing of design decisions.
Is a 7 Star Energy Rating different from a NatHERS assessment?A 7 Star Energy Rating usually refers to the result of a NatHERS thermal performance assessment. NatHERS is the assessment method, while 7 stars is the rating outcome being targeted or achieved.
Can a project still pass if it does not reach 7 stars at first?Often the design can be adjusted, but the difficulty depends on the project. Some changes may be simple, while others may affect glazing, shading, insulation, construction details or layout. Early assessment gives the team more options.
Does Whole of Home replace NatHERS?No. NatHERS thermal performance and Whole of Home energy performance assess different parts of the residential energy pathway. NatHERS focuses on the building fabric and heating and cooling demand, while Whole of Home considers major fixed energy systems.
When should I send my plans for assessment?Send your plans once the design is developed enough to show layout, orientation, elevations, glazing and construction information. If the design is still evolving, an early review can help identify likely NatHERS issues before the project is fully locked in.