Residential Compliance Pathways
NatHERS, BASIX and BESS are often mentioned together, but they are not the same assessment. Each one applies in a different context and measures a different part of residential sustainability or energy compliance.
In brief: NatHERS is a national home energy rating scheme focused on thermal performance. BASIX is a NSW residential sustainability assessment covering water, energy and thermal performance. BESS is a Victorian local government sustainability assessment tool commonly used at planning permit stage. The right pathway depends on your project location, building type and approval requirements.
NatHERS, BASIX and BESS all relate to better residential building performance, so it is easy to group them together. They may also appear on the same project, depending on the state, council, building type and approval pathway.
The key difference is scope. NatHERS focuses on how the home performs thermally. BASIX is a NSW planning and approval requirement for residential sustainability. BESS is a Victorian council planning tool used to demonstrate environmentally sustainable design outcomes. Understanding the role of each assessment helps avoid missing the right requirement or preparing the wrong report.
Thermal Performance
Start here for home energy ratings, NatHERS certificates and thermal performance assessment.
NSW Residential
Understand NSW residential sustainability requirements for water, energy and thermal performance.
Victorian Planning
Learn how BESS supports ESD outcomes for Victorian planning permit applications.
NatHERS stands for the Nationwide House Energy Rating Scheme. It provides energy ratings for homes and is used to assess how much heating and cooling a dwelling is expected to need to stay comfortable. NatHERS ratings use a 0 to 10 star scale, where a higher rating generally indicates better thermal performance and lower heating and cooling demand.
A NatHERS assessment considers the home’s design, orientation, construction materials, glazing, insulation and local climate. It is commonly used for new homes and major renovations, and NatHERS is also being expanded to include existing home energy ratings. For current new home projects, NatHERS is often discussed in relation to 7 Star requirements and Whole of Home energy performance.
BASIX stands for Building Sustainability Index. It is a NSW residential sustainability assessment that forms part of the development application process. BASIX standards cover water, energy use and thermal performance for residential development in New South Wales.
A BASIX Certificate may be required for new residential developments, renovations above the relevant threshold and some pools or spas in NSW. NatHERS may be used as part of the thermal performance pathway within BASIX, but BASIX is broader than NatHERS because it also considers water and energy commitments.
BESS stands for Built Environment Sustainability Scorecard. It is a sustainability assessment tool created by local governments in Victoria. BESS is commonly used at planning permit stage to help applicants and councils demonstrate environmentally sustainable design outcomes.
BESS is broader than thermal performance alone. It can consider categories such as energy, water, indoor environment quality, transport, waste, urban ecology, stormwater and innovation, depending on the project type and council requirements. It may apply to residential, mixed-use or other developments in participating Victorian council areas.
| Assessment | Where it applies | What it focuses on | Common use |
|---|---|---|---|
| NatHERS | National scheme | Thermal performance, heating and cooling demand | Home energy ratings and NatHERS certificates |
| BASIX | New South Wales | Water, energy and thermal performance | NSW residential development applications |
| BESS | Victorian council planning context | Environmentally sustainable design across several categories | Planning permit support for Victorian projects |
You may need a NatHERS assessment when a residential project requires a thermal performance rating. This is common for new homes, townhouses, apartments and some major renovations. The assessment helps show how the home is expected to perform thermally before it is built.
NatHERS may also sit inside another pathway. For example, in NSW, NatHERS modelling can help support the thermal performance component of BASIX. In other states, NatHERS may form part of the residential energy efficiency pathway under the National Construction Code.
You generally need BASIX when your residential project is in New South Wales and falls within the BASIX requirements. BASIX is part of the NSW planning and approval process, so it is often needed before a construction certificate or complying development certificate can be issued.
Because BASIX covers water, energy and thermal performance, it can involve more than a NatHERS rating alone. The project may need commitments around fixtures, water use, heating and cooling systems, hot water, glazing, insulation and other design or specification items.
You may need BESS when a Victorian council requires an environmentally sustainable design assessment as part of a planning permit application. BESS is used by participating councils to assess how a proposed development responds to sustainability objectives.
For some Victorian projects, BESS may sit alongside other requirements such as energy ratings, stormwater management, daylight, indoor environment quality or broader ESD documentation. The exact requirements depend on the council, project type and planning pathway.
Yes. These assessments are not always mutually exclusive. A NSW residential project may need BASIX and use NatHERS modelling for the thermal performance component. A Victorian project may need BESS for the planning stage and NatHERS for the building energy rating pathway.
This is why project location matters. The same building design may have different assessment requirements depending on whether it is located in NSW, Victoria or another state or territory. Council requirements, approval pathway and project scale can also change the documentation needed.
The best starting point is usually the project location and approval pathway. If the project is in NSW, BASIX is often the first residential sustainability framework to check. If the project is in Victoria and requires a planning permit, BESS or another ESD pathway may need to be considered. If the project needs a residential energy rating, NatHERS may be part of the pathway.
In practice, the assessments should not be treated as separate last-minute tasks. Thermal performance, water efficiency, energy systems, glazing, insulation, shading, stormwater and planning requirements can affect each other. Early review helps identify the right pathway and reduce avoidable redesign or duplicated documentation.
Certified Energy can review your residential project documents and advise whether NatHERS, BASIX, BESS, Whole of Home or another sustainability assessment pathway applies.
No. NatHERS is a national home energy rating scheme focused on thermal performance. BASIX is a NSW residential sustainability assessment that covers water, energy and thermal performance. NatHERS modelling can be used as part of the BASIX thermal performance pathway.
Is BESS the same as BASIX?No. BASIX applies to residential development in NSW. BESS is a Victorian local government sustainability assessment tool used by participating councils, often at planning permit stage.
Can a project need both NatHERS and BASIX?Yes. In NSW, BASIX is the broader residential sustainability pathway, while NatHERS modelling may be used to support the thermal performance component of BASIX.
Can a Victorian project need both BESS and NatHERS?Yes. Some Victorian projects may need BESS or another ESD assessment at planning permit stage and a NatHERS rating for residential energy performance. The exact requirements depend on the council, building type and approval pathway.
How do I know which assessment applies?Start with the project location, building type and approval pathway. NSW residential projects often need BASIX. Victorian planning applications may need BESS or another ESD pathway. NatHERS may apply where a residential thermal performance rating is required.