NatHERS Design Principles
6 Star NatHERS Assessment Design Tips and the Shift to 7 Star Homes
6 Star NatHERS was once the familiar benchmark for many new residential projects in Australia. Today, many new homes are considered in the context of 7 Star NatHERS requirements, Whole of Home energy performance and a stronger focus on comfort, building fabric and design quality.
Updated context: This article was originally written when 6 Star NatHERS was the common minimum benchmark for many new homes. Since then, the residential energy efficiency context has shifted. Under NCC 2022, many new residential projects are now assessed in relation to higher thermal performance expectations, including 7 Star NatHERS requirements and Whole of Home energy performance. The design principles below still matter, but the compliance context has changed.
Why 6 Star NatHERS Still Matters
Many homeowners, builders and designers still search for 6 Star NatHERS advice because the term was used for many years in residential energy compliance. Older project documents, previous approvals, established builder language and earlier blog articles may still refer to 6 Star energy ratings.
That does not mean 6 Star should be treated as the current design target for every new home. The more useful way to read older 6 Star guidance is as a foundation. The same passive design principles that helped homes reach 6 Stars often still influence whether a project can perform well under newer NatHERS expectations.
What Changed With 7 Star NatHERS?
NatHERS assessments measure the thermal performance of a home by modelling how much heating and cooling may be needed to keep the dwelling comfortable. A higher star rating generally indicates that the home is expected to require less artificial heating and cooling to maintain comfort.
With the move toward 7 Star NatHERS and Whole of Home energy performance, residential energy compliance has become less forgiving of weak design decisions. Glazing, orientation, insulation, shading, ventilation, roof colour and construction quality can all have a stronger effect on the final pathway.
This is why early design thinking matters. It is usually easier to improve thermal performance while the design is still flexible than to solve rating problems after plans, elevations, glazing schedules and construction details are already locked in.
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NatHERS Knowledge Hub
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Current Context
7 Star NatHERS Rating
Learn what the 7 Star NatHERS requirement means for new residential projects.
Design Principles That Still Matter
Although the benchmark has changed, the fundamentals have not disappeared. A home that performs well in NatHERS is usually not the result of one product or one last-minute upgrade. It is usually the result of many design decisions working together.
1. Orientation
Orientation affects how a home receives sun, shade and heat across the day and across the seasons. Good orientation can support winter warmth, reduce unwanted summer heat gain and make living spaces more comfortable without relying as heavily on mechanical heating and cooling.
North-facing living areas can often be easier to manage with appropriate shading, while east and west glazing can create stronger morning and afternoon heat gain. The right orientation strategy depends on the climate zone, site constraints, neighbouring buildings and the overall design.
2. Glazing Size and Placement
Windows can have a major influence on NatHERS outcomes because they affect heat gain, heat loss, daylight, views and ventilation. Large areas of glazing may improve connection to outdoors, but they can also make a home harder to heat or cool if they are not carefully designed.
A better NatHERS result often comes from balancing glazing area, orientation, frame type, glass performance and shading. The aim is not always to remove glazing. The aim is to place it carefully and specify it appropriately for the project.
3. Shading
Shading can make a significant difference to thermal performance, especially where glazing receives strong summer sun. Eaves, awnings, pergolas, screens, balconies and adjacent built form can all influence how much solar heat enters the home.
The best shading strategy is climate-responsive. In cooler climates, the design may need to preserve useful winter sun. In warmer climates, reducing unwanted heat gain may be more important. Shading should be considered as part of the architecture rather than as a late add-on.
4. Insulation and Building Fabric
The building fabric is central to NatHERS performance. Walls, roofs, floors, ceilings, windows and doors all contribute to how well the home resists unwanted heat flow. If the building fabric is weak, the home may be more vulnerable to both winter heat loss and summer heat gain.
Insulation levels matter, but so does the way insulation is installed and coordinated with the rest of the construction. Gaps, compression, thermal bridging and poorly resolved junctions can reduce the real performance of the home.
5. Roof Colour and Solar Exposure
Roof colour can influence heat absorption, particularly in warmer climates or on exposed sites. Darker roof colours generally absorb more solar heat, while lighter colours can help reduce heat gain. The effect will depend on climate, roof construction, insulation, ceiling design and the rest of the building fabric.
A roof colour decision should not be treated in isolation. It is one part of a broader thermal strategy that also includes insulation, ventilation, ceiling construction, roof form and the local climate.
6. Ventilation, Zoning and Comfort
Natural ventilation, internal zoning and room layout can all influence how a home feels and performs. Cross-ventilation, operable windows, ceiling heights, internal doors and the relationship between living and sleeping areas can affect comfort across the day.
Zoning can also help separate spaces with different heating and cooling needs. A well-zoned home may be easier to condition efficiently because the whole dwelling does not always need to operate as one open volume.
Why Early NatHERS Advice Matters More Now
When 6 Star was the common benchmark, some projects could still pass with relatively simple changes. Under a higher-performance context, the margin for late-stage fixes can be smaller. A design that is already well oriented, appropriately glazed and properly insulated is usually easier to assess than a design that needs major changes late in documentation.
A NatHERS assessor can help identify which parts of the design are doing the most work and which areas may be holding the rating back. This can help project teams make more targeted decisions instead of relying on generic upgrades.
Need a NatHERS Assessment for Your Project?
Certified Energy can review your plans and advise what NatHERS, BASIX, Whole of Home or related residential energy compliance pathway may apply to your project.
Related Guides
- NatHERS Knowledge Hub
- 7 Star NatHERS Rating
- BASIX vs NatHERS: What Is the Difference?
- Passive Design Principles for BASIX and NatHERS
FAQ
Is 6 Star NatHERS still the standard for new homes?
6 Star NatHERS was a common benchmark for many years, but many new residential projects are now considered in the context of 7 Star NatHERS requirements and Whole of Home energy performance under NCC 2022. Requirements can vary by project type, state, territory and timing, so project-specific advice is important.
Why do people still search for 6 Star NatHERS assessments?
Many homeowners, builders and designers still search for 6 Star NatHERS because the term was used for many years in residential energy compliance. Older project documents, previous approvals and established builder language may still refer to 6 Star energy ratings.
Do old 6 Star design tips still help with 7 Star NatHERS?
Yes. Orientation, glazing, shading, insulation, roof colour, ventilation and zoning still influence NatHERS outcomes. The difference is that a higher-performance target often requires these decisions to work together more carefully.
Can a NatHERS rating be improved after the design is complete?
Sometimes, but late changes can be more limited or more expensive. It is usually better to consider NatHERS early, while glazing, shading, insulation, orientation and construction details can still be adjusted.
What should I send for a NatHERS assessment?
A NatHERS assessor usually needs architectural plans, elevations, sections, window and door information, construction details and project location information. If you are unsure whether the documentation is ready, you can send what you have for review.
