NatHERS Compliance
Is NatHERS Mandatory in Australia?
NatHERS is one of the main ways Australian residential projects demonstrate thermal performance. Whether it is required depends on the project type, location, approval pathway and the energy efficiency requirements that apply.
Mandatory NatHERS in brief
NatHERS is commonly used to demonstrate energy efficiency compliance for new homes in Australia. Under updated National Construction Code residential energy settings, new homes generally need to meet minimum thermal performance requirements, often through a NatHERS star rating or equivalent pathway. However, the exact requirement can vary depending on the state or territory, project type, approval timing and compliance pathway.
When NatHERS is usually required
NatHERS is most commonly required for new residential projects where the energy efficiency pathway uses a thermal star rating. This can include new houses, townhouses and apartments, depending on the project and jurisdiction.
In these situations, the NatHERS assessment models the proposed design and produces a thermal star rating. That rating helps demonstrate how well the building fabric is expected to perform in its local climate and how much heating and cooling the home may need to remain comfortable.
NatHERS is not the only possible compliance pathway in every situation, but it is one of the most widely used and recognised ways to show residential thermal performance under Australian energy efficiency requirements.
How NatHERS relates to the National Construction Code
The National Construction Code sets minimum performance requirements for new buildings in Australia, including residential energy efficiency requirements. NatHERS supports these requirements by providing a consistent way to assess thermal performance for homes.
Recent NCC changes introduced a new minimum 7 star thermal performance requirement or equivalent, as well as a Whole of Home annual energy use budget. The thermal star rating focuses on heating and cooling needs, while Whole of Home considers broader energy use across the dwelling.
This means a new home may need to satisfy both a thermal performance requirement and a broader home energy requirement. The exact pathway should be checked for the specific project and jurisdiction.
The practical point
NatHERS is not just a voluntary design score for many new homes. It is commonly part of the formal energy compliance pathway.
The exact requirement should always be confirmed against the project location, building class, approval stage and applicable state or territory rules.
Is 7 Star NatHERS mandatory?
For many new residential projects, the key question is no longer only whether NatHERS applies, but what star rating is required. Under NCC 2022 residential energy efficiency settings, new homes generally move toward a minimum 7 star thermal performance requirement or equivalent.
However, implementation can vary between states and territories. Transitional arrangements, approval timing, state based tools and project specific pathways can all affect which requirement applies at a particular point in time.
For this reason, it is safer to treat 7 Star NatHERS as a major current benchmark for new homes, while still confirming the exact requirement for the project. For more detail, see our 7 Star Rating guidance.
Does NatHERS apply in NSW?
In NSW, residential energy compliance is commonly handled through BASIX. NatHERS modelling may be used to support the thermal performance component of the BASIX pathway for many projects.
This means NSW projects often involve both BASIX and NatHERS, but they are not the same document. BASIX is the NSW sustainability certificate. NatHERS is the thermal modelling pathway that may support the thermal performance outcome.
If the project is in NSW, the correct pathway should be checked against the project type, approval stage and BASIX requirements before finalising documentation.
Common project types where NatHERS may be relevant
• New detached homes
• Townhouses and dual occupancies
• Multi residential apartment projects
• Alterations and additions where energy efficiency assessment is triggered
• Projects where a thermal performance pathway is required for approval
Do renovations require NatHERS?
Renovations, additions and alterations can be more complex than new homes. Some projects may trigger energy efficiency requirements, while others may not require a full NatHERS assessment. The answer depends on the scope of works, jurisdiction and approval pathway.
For example, a substantial addition or major alteration may need energy performance documentation, especially if it changes the building envelope or creates new habitable areas. Smaller works may follow a different pathway or require fewer inputs.
Because renovation requirements are project specific, it is best not to assume. If the project involves an existing home, it may also be useful to understand the difference between new home NatHERS compliance and Home Energy Rating for existing homes.
What happens if NatHERS is required?
If NatHERS is required, the project team will usually need to provide enough design information for the home to be modelled. This includes plans, elevations, sections, orientation, construction details, insulation, glazing, shading and other building fabric information.
The assessor models the design using accredited NatHERS software and calculates the thermal star rating. If the rating does not meet the required level, the design may need changes to glazing, insulation, shading, roof colour, construction details or other thermal performance features.
Once the pathway is resolved, the assessment outcome can support the required approval documentation. In NSW, this may also need to align with the BASIX certificate and related commitments.
Why requirements vary by state and territory
Although the NCC is a national code, adoption and implementation can involve state and territory arrangements. This means timing, transitional provisions and administrative pathways may not be identical across Australia.
Some jurisdictions may apply enhanced local systems, specific certificate processes or transitional rules. Others may adopt new NCC settings on a different timeline. This is one reason residential energy compliance should be checked early rather than assumed from another project.
For design teams working across multiple states, this is especially important. A pathway that was correct for one location may not be correct for another.
Common misunderstanding
NatHERS should not be treated as optional just because the exact pathway can vary.
For many new residential projects, thermal performance assessment is a formal part of the approval process, and NatHERS is often the pathway used to demonstrate it.
Design considerations for Australian homes
If NatHERS is likely to be required, it should be considered before the design is locked in. Thermal performance can be affected by early architectural decisions such as orientation, window size, shading, roof design, floor construction and material selection.
Leaving the assessment until the end can make compliance harder. At that point, the project team may have fewer options if the rating needs improvement, and changes may affect drawings, specifications, BASIX commitments or construction documentation.
Early review helps clarify whether the project is on the right pathway and whether the design is likely to meet the applicable residential energy requirements.
Working with Certified Energy
Certified Energy provides NatHERS assessments for new homes, townhouses and multi residential projects across Australia. Our team reviews the project documentation, models the design and helps identify the thermal performance pathway required for the project.
Where relevant, we can also help connect the assessment with related requirements including BASIX, 7 Star Rating, 6 Star NatHERS and Whole of Home.
For a broader explanation of the rating framework, visit our NatHERS Knowledge Hub.
FAQ
Is NatHERS mandatory in Australia?
NatHERS is commonly used to demonstrate residential energy efficiency compliance for new homes. Whether it is required depends on the project type, location, approval pathway and applicable state or territory requirements.
Is 7 Star NatHERS mandatory?
NCC 2022 introduced a new minimum 7 star thermal performance requirement or equivalent for new homes, along with Whole of Home energy requirements. Implementation and transitional timing can vary by state and territory.
Does BASIX replace NatHERS in NSW?
No. BASIX is the NSW sustainability certificate. NatHERS modelling may be used to support the thermal performance component of the BASIX pathway for many NSW residential projects.
Do renovations require NatHERS?
Some renovations, additions or alterations may require energy efficiency assessment, depending on the scope, location, building approval pathway and relevant jurisdictional requirements.
When should NatHERS be checked?
NatHERS should be checked before the design is fully locked in. Early review gives the project team more flexibility to resolve glazing, insulation, shading, roof colour and other thermal performance details.
