NatHERS Star Ratings
What Is a 7 Star NatHERS Rating?
A 7 Star NatHERS rating is a key benchmark for new Australian homes. It shows that the home’s thermal design is expected to reduce heating and cooling demand compared with lower rated homes.
7 Star NatHERS in brief
A 7 Star NatHERS rating means a home has been modelled to achieve a higher level of thermal performance on the NatHERS 0 to 10 star scale. The rating reflects the predicted heating and cooling needs of the home based on its design, construction, materials and local climate. In many new residential projects, 7 Stars is now an important compliance benchmark under updated Australian energy efficiency requirements.
What 7 Stars means in practice
A 7 Star NatHERS rating does not mean the home uses no energy. It means the home’s thermal performance has been modelled at a level where it is expected to need less heating and cooling than a lower rated home in the same climate.
The rating is based on the building fabric. This includes the walls, roof, floor, windows, insulation, shading, orientation and construction details that influence how the home responds to heat and cold.
For homeowners and design teams, 7 Stars is useful because it turns thermal performance into a clear benchmark. It helps show whether the home is likely to remain comfortable with less reliance on mechanical heating and cooling.
Why 7 Stars became more important
For many years, 6 Stars was the common residential thermal performance benchmark across much of Australia. The move toward 7 Stars reflects a broader shift in how new homes are expected to perform.
The change is not only about reducing energy use. It is also about improving comfort, resilience and the long term performance of Australian housing. A home that is designed to manage heat and cold more effectively can be more comfortable to live in and less dependent on heating and cooling systems.
Because implementation can vary by state, territory and project pathway, it is important to confirm the requirements that apply to the specific project location and approval stage.
7 Stars is not just a product upgrade
A 7 Star rating is rarely achieved by changing one item in isolation. It usually comes from the way the whole design works together.
Glazing, insulation, shading, orientation, roof design, construction materials and climate response all influence the final NatHERS result.
What affects a 7 Star NatHERS result?
A 7 Star result is shaped by the interaction between the home and its climate. The same design may perform differently in different parts of Australia because temperature patterns, humidity, solar exposure and seasonal conditions vary.
Key design factors include:
• Orientation and solar access
• Window size, placement, frame type and glazing specification
• Ceiling, wall, roof and floor insulation
• Eaves, awnings, balconies and external shading
• Roof colour and external surface properties
• Construction type, thermal mass and floor system
• Local climate zone and seasonal heating or cooling needs
In some projects, improving the rating may involve increasing insulation. In others, the bigger issue may be excessive west facing glazing, limited shading, dark roof colours or poor solar control. This is why the assessment needs to respond to the actual design rather than follow a generic checklist.
How 7 Stars relates to NatHERS and Whole of Home
The 7 Star NatHERS rating is about thermal performance. It focuses on the heating and cooling needs created by the home’s design and building fabric.
Whole of Home is related, but it looks at a broader energy picture. It considers major energy uses such as heating and cooling equipment, hot water, appliances, lighting, solar and batteries where applicable.
This means a project may need to consider both the thermal star rating and Whole of Home requirements. The NatHERS result shows how well the home’s shell performs, while Whole of Home looks more broadly at energy use and onsite generation.
How 7 Stars relates to BASIX in NSW
In NSW, residential projects often need to consider NatHERS in the context of BASIX. BASIX includes broader sustainability requirements, while NatHERS modelling may be used to demonstrate the thermal performance component of the design.
This can make early coordination important. A design decision that affects the NatHERS rating may also affect BASIX commitments, documentation and the overall compliance pathway.
Common reason projects struggle to reach 7 Stars
Many projects do not struggle because one item is missing. They struggle because the design has several small performance pressures at the same time.
Large exposed glazing, limited shading, unfavourable orientation, insufficient insulation or construction details that are not fully resolved can all combine to lower the rating.
Design considerations for Australian homes
A 7 Star outcome is easier to achieve when thermal performance is considered during design, not after the home has already been fully resolved. Early review gives the project team more room to adjust window proportions, shading, insulation levels and material selections.
This is especially important for homes with large areas of glazing, complex forms, exposed upper levels, lightweight construction or challenging orientations. These features can still be part of a strong design, but they need to be balanced carefully.
The aim is not to make every home look the same. The aim is to help each design respond intelligently to its site, climate and compliance requirements.
Working with Certified Energy
Certified Energy provides NatHERS assessments for new homes, townhouses and multi residential developments across Australia. Our team reviews the project documentation, models the proposed design and helps identify practical pathways toward the required thermal performance outcome.
Where a project is targeting or required to achieve 7 Stars, we can help the design team understand which parts of the building fabric are influencing the result. This may include glazing, insulation, orientation, shading, roof colour, floor construction or other design details.
We can also help connect the assessment with related requirements, including NatHERS, BASIX, Whole of Home and project specific residential energy compliance.
For more detail on the broader rating framework, visit our NatHERS Knowledge Hub.
FAQ
What is a 7 Star NatHERS rating?
A 7 Star NatHERS rating is a thermal performance rating that indicates the home is expected to need less heating and cooling than a lower rated home to remain comfortable in its local climate.
Is 7 Stars mandatory for new homes?
Under NCC 2022 residential energy efficiency settings, new homes generally move toward a 7 Star thermal performance requirement, but implementation and transitional arrangements can vary by state, territory and approval pathway.
Does 7 Stars mean the home will have low energy bills?
A 7 Star thermal rating generally means the home should need less heating and cooling, but actual energy bills also depend on occupant behaviour, appliance efficiency, hot water systems, solar, batteries, energy tariffs and how the home is used.
Can a design be improved to reach 7 Stars?
Often, yes. Depending on the design, improvements may involve glazing changes, added shading, better insulation, adjusted roof colour, revised construction details or other thermal performance measures.
Is 7 Stars the same as Whole of Home?
No. A 7 Star NatHERS rating relates to the thermal performance of the home. Whole of Home considers broader energy use and generation, including major appliances, hot water, heating and cooling systems, solar and batteries where applicable.
