NatHERS Foundations
Why Does Australia Use NatHERS?
Australia uses NatHERS because homes perform differently in different climates. A house that feels comfortable in one location may overheat, lose warmth or need more heating and cooling somewhere else.
NatHERS in brief
Australia uses NatHERS to assess the thermal performance of homes before they are built. The rating estimates how much heating and cooling energy a home may need to maintain comfortable indoor conditions in its local climate. This helps connect design decisions with comfort, energy demand and residential compliance.
Australia has many different housing climates
One reason Australia uses NatHERS is that Australian homes are built across very different climate conditions. Coastal, inland, alpine, tropical, hot dry, humid and cool temperate locations all create different comfort challenges.
A design that works well in one climate may not perform well in another. The same window layout, roof colour, insulation level or shading strategy can produce different outcomes depending on local weather, sun exposure and seasonal conditions.
NatHERS helps assess the home in the climate where it will actually be built, rather than treating every home as if it performs the same everywhere.
It makes thermal performance visible before construction
Before a home is built, it can be difficult to know how comfortable it will feel. Plans show layout, structure and appearance, but they do not always reveal how much heating or cooling the home may need across the year.
NatHERS provides a way to model the home’s thermal behaviour before construction. It considers the design, building fabric, windows, shading, insulation, orientation and climate, then produces a thermal star rating.
This makes performance easier to discuss during design, rather than discovering comfort problems only after the home is occupied.
The practical point
NatHERS helps move comfort from guesswork into design review.
It shows how the proposed home is expected to respond to its climate before it is built.
It supports better building fabric decisions
NatHERS focuses heavily on the building fabric because the physical envelope of the home shapes heating and cooling demand. The roof, ceiling, walls, floors, windows, doors, insulation, shading and air leakage assumptions all influence the result.
Without a thermal performance assessment, these details can be treated as isolated specifications. NatHERS helps show how they work together as a system.
For more detail, see our guide to why building fabric matters.
It helps reduce reliance on heating and cooling
A better performing home should need less mechanical correction to maintain comfort. That does not mean a home will never use heating or cooling. It means the home’s design and fabric should reduce the amount of work those systems need to do.
NatHERS supports this by estimating heating and cooling demand based on the proposed design. If the demand is high, the project team can review what is driving it and consider targeted improvements.
This is why NatHERS is connected to both comfort and energy efficiency, not just approval paperwork.
NatHERS helps project teams consider:
• Local climate and climate zone
• Orientation and room layout
• Window size, frame type and glazing performance
• External shading and solar heat gain
• Ceiling, roof, wall and floor insulation
• Roof colour, floor construction, thermal mass and air leakage assumptions
It gives a shared performance language
NatHERS gives architects, designers, builders, homeowners, developers, assessors and certifiers a shared way to discuss thermal performance. Instead of only saying a home is “energy efficient”, the project team can refer to a modelled rating and the design details behind it.
This matters because comfort and performance are affected by many small decisions. A shared rating framework helps make those decisions easier to coordinate.
For a foundation explanation, see our guide to what NatHERS is.
Common misunderstanding
NatHERS is sometimes seen only as a compliance hurdle.
In practice, it can also help explain why a home is likely to feel more or less comfortable in its climate.
It supports climate responsive design
Climate responsive design means shaping the home around the conditions where it will be built. NatHERS supports this by testing the home against local climate data rather than applying a generic national assumption.
A climate responsive home considers orientation, sun path, shading, glazing, insulation, ventilation, roof colour and materials in relation to the site. These decisions can improve comfort and reduce heating and cooling demand.
For more detail, see our guide to why climate responsive design matters for NatHERS.
It helps identify design pressure points
When a home does not reach the required rating, NatHERS can help identify where the performance pressure is coming from. It may be glazing, shading, roof colour, insulation, floor construction, thermal mass, orientation or another part of the building fabric.
This allows the project team to make targeted changes rather than guessing. In many cases, a focused adjustment can be more useful than adding expensive upgrades everywhere.
For more detail, see our guide to what happens if a home fails NatHERS.
It connects to broader home energy performance
NatHERS focuses on thermal performance: the heating and cooling energy a home may need to stay comfortable. Broader home energy performance can also include fixed appliances, hot water, heating and cooling systems, solar and batteries where applicable.
This is where NatHERS connects with Whole of Home. NatHERS helps explain the thermal demand. Whole of Home helps broaden the view to the home’s energy systems and fixed appliance choices.
Together, these approaches support a more complete understanding of home performance.
How NatHERS connects to compliance
NatHERS is often used as part of the residential energy compliance pathway for new homes, townhouses and apartments. It may connect with 7 Star Rating, Whole of Home and state based systems such as BASIX in NSW.
The compliance outcome matters, but the deeper value is that the rating helps show how the home is expected to perform thermally. A stronger pathway is one where the design, documentation and comfort intent are aligned early.
For the complete framework, visit our NatHERS Knowledge Hub.
Design considerations for Australian homes
Australian homes need design decisions that respond to climate, orientation and everyday use. NatHERS supports this by helping project teams understand how the proposed home is likely to behave before construction begins.
The best results usually come from treating thermal performance as part of the design process, not as a late adjustment. Window placement, shading, roof colour, insulation, floor construction and thermal mass can all be coordinated earlier with less disruption.
A well resolved NatHERS pathway should support both approval and the lived comfort of the home.
Working with Certified Energy
Certified Energy provides NatHERS assessments for new homes, townhouses and multi residential projects across Australia. Our team can model the home, review the building fabric and help project teams understand how design decisions affect the thermal star rating.
Where needed, we can help connect NatHERS with related requirements such as NatHERS, BASIX, 7 Star Rating and Whole of Home.
For the broader assessment framework, visit our NatHERS Knowledge Hub.
FAQ
Why does Australia use NatHERS?
Australia uses NatHERS to assess the thermal performance of homes and estimate how much heating and cooling energy they may need to stay comfortable in their local climate.
What problem does NatHERS help solve?
NatHERS helps make home thermal performance clearer before construction by showing how design decisions such as glazing, shading, insulation, orientation and building fabric affect heating and cooling demand.
Is NatHERS only about compliance?
No. NatHERS is often used for compliance, but it also helps project teams understand comfort, climate response and the thermal performance of the proposed home.
Why does climate matter in NatHERS?
Climate matters because the same home design can perform differently in different parts of Australia. NatHERS assesses the home in relation to the climate where it will be built.
Does NatHERS replace good design?
No. NatHERS does not replace good design. It helps test whether the design, building fabric and climate response are likely to support thermal comfort and lower heating and cooling demand.
