NatHERS Star Ratings
What Is Considered a Good NatHERS Rating?
A good NatHERS rating is not only about reaching a number. It is about whether the home’s thermal performance is suitable for its climate, design intent, compliance pathway and long term comfort.
Good NatHERS ratings in brief
A good NatHERS rating is one that meets the required compliance pathway and supports a comfortable, climate responsive home. For many current new homes, 7 Stars or equivalent is an important benchmark. Ratings above this may indicate stronger thermal performance, but the right target depends on the project location, design, budget and long term performance goals.
What a good rating means in practice
A NatHERS rating measures the predicted thermal performance of a home on a scale from 0 to 10 stars. The rating estimates how much heating and cooling the home may need to remain comfortable in its local climate.
In practical terms, a good rating means the home’s building fabric is doing a reasonable amount of work before mechanical heating or cooling is needed. The design should be responding to climate through its orientation, insulation, glazing, shading, construction materials and roof or floor systems.
A good rating is also relative to the project’s requirements. A rating that was acceptable under an older pathway may not be enough for a current new home. A higher performance brief may call for a rating beyond the minimum compliance target.
Is 7 Stars a good NatHERS rating?
For many current new homes, a 7 Star NatHERS rating is an important benchmark. It generally indicates stronger thermal performance than the older 6 Star benchmark and reflects the broader shift toward better performing residential buildings.
A 7 Star home is expected to need less heating and cooling than a lower rated home in the same climate. This can support improved comfort, reduced heating and cooling demand and a more resilient building fabric.
However, 7 Stars should still be understood in context. The result depends on the home’s climate zone, design assumptions, construction details and the accuracy of the information provided for assessment.
The practical point
A good NatHERS rating is not just the highest number possible.
It is a rating that meets the project’s compliance requirements while supporting a home that is comfortable, buildable and appropriate for its climate.
How 6, 7 and 8 Star ratings compare
The NatHERS scale is continuous, but the common industry conversation often focuses on 6, 7 and 8 Star homes. Each rating level gives a different indication of expected heating and cooling demand.
A simple way to understand the difference
6 Stars: historically common and generally good, but often below the current benchmark for many new homes.
7 Stars: a strong current benchmark for many new homes and residential compliance pathways.
8 Stars and above: higher performance targets that may support stronger comfort and lower heating and cooling demand when practical for the project.
For more detail, see our guides to 6 Star NatHERS, 7 Star NatHERS and 8 Star homes.
Is a higher rating always better?
A higher NatHERS rating generally means the home is expected to need less heating and cooling to remain comfortable. From a thermal performance perspective, higher is usually stronger.
But the best target still needs to make sense for the project. A higher rating may require design changes, specification upgrades or construction details that need to be balanced with budget, architecture, site constraints and buildability.
For some homes, moving above minimum compliance may be practical and valuable. For others, a well resolved compliance rating with strong Whole of Home decisions may be the better balanced outcome.
What makes a rating good in one climate may not work in another
NatHERS ratings are climate specific. A home’s star rating is calculated using climate data for its location, which means a design response that works well in one region may not be appropriate somewhere else.
In cooler climates, a good rating may depend heavily on insulation, heat retention, glazing performance and winter solar access. In hotter climates, shading, roof colour, solar control, ventilation and reducing cooling loads may become more important.
This is why the right rating strategy should respond to the relevant NatHERS climate zone, not just a generic performance checklist.
Features that often support a good rating
• Climate responsive orientation and layout
• Well placed and well specified glazing
• Appropriate external shading
• Continuous ceiling, roof, wall and floor insulation
• Suitable roof colour and construction materials
• Early coordination between design and thermal modelling
How a good rating connects to compliance
For many new residential projects, a good NatHERS rating is first one that satisfies the applicable compliance pathway. This may involve current thermal performance requirements, state or territory rules and project specific approval conditions.
In NSW, the rating may also need to align with BASIX documentation. For broader residential energy outcomes, the project may also need to consider Whole of Home requirements.
This means the star rating should not be reviewed in isolation. It sits within the broader residential compliance and performance pathway for the home.
A balanced way to decide
Start with the rating required for compliance.
Then ask whether aiming higher would genuinely improve comfort, resilience or long term value for the project.
The best answer comes from modelling the actual design, not assuming the same target suits every home.
Design considerations for Australian homes
A good NatHERS rating is easier to achieve when the design responds to climate from the beginning. Orientation, glazing, shading, roof form, insulation and construction systems can all influence the result before product upgrades are considered.
If the design has large areas of glazing, complex forms, exposed floors, raked ceilings or challenging orientations, early modelling can help identify pressure points before they become difficult to change.
The goal is not to make every home chase the same number. The goal is to create a home that meets its requirements and performs well for the people who will live in it.
Working with Certified Energy
Certified Energy provides NatHERS assessments for new homes, townhouses and multi residential projects across Australia. Our team can model the proposed design and help identify whether the rating meets the relevant compliance pathway.
Where a project is aiming for stronger performance, we can help the design team understand which factors are influencing the rating, including glazing, insulation, shading, orientation, roof colour, floor construction and climate zone. We can also help connect the assessment with related requirements such as NatHERS, 7 Star Rating, BASIX and Whole of Home.
For a broader explanation of the rating framework, visit our NatHERS Knowledge Hub.
FAQ
What is considered a good NatHERS rating?
A good NatHERS rating depends on the project, climate zone and compliance requirement. For many current new homes, 7 Stars or equivalent is an important benchmark, while higher ratings may indicate stronger thermal performance.
Is 7 Stars a good NatHERS rating?
Yes. A 7 Star NatHERS rating is generally considered a strong current benchmark for many new homes because it indicates improved thermal performance compared with older lower benchmarks.
Is 8 Stars better than 7 Stars?
An 8 Star home generally has stronger predicted thermal performance than a 7 Star home in the same climate. Whether it is worth targeting depends on the project brief, budget, site and design strategy.
Is a higher NatHERS rating always better?
A higher rating generally means the home is expected to need less heating and cooling, but the best target should still be balanced with compliance, comfort, budget, design intent and buildability.
Can a good rating vary by climate zone?
Yes. NatHERS ratings are climate specific. A design strategy that works well in one climate zone may need to be adjusted for another location.
