A NatHERS energy assessment helps you, your designer, architect and builder, make good design and appliance choices so that your new, or renovated home uses less energy and is more comfortable to live in. An energy efficient home also has a higher resale value when the time comes to sell your property.
NatHERS assessments are also used to meet minimum energy efficiency requirements in the National Construction Code (NCC). These have changed in a number of states and territories recently.
A NatHERS Accredited Assessor can guide the design of your home to meet the NCC, while also providing advice on how to reduce your heating and cooling needs. In addition to helping meet regulations, NatHERS ratings can also be used to:
- guide the inclusion of the best appliances to support an energy efficient home; and
- seek information on the energy performance of an advertised property in the future.
From mid-2025 NatHERS will also provide ratings for existing homes. These assessments can help homeowners improve their home’s energy performance and save on bills.
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NatHERS star ratings
The NatHERS star rating is included in an energy assessment for a new home, major renovation or existing home.
NatHERS star ratings provide information about the thermal performance (heating and cooling needs) of a home. A star rating is out of 10 and considers a home’s design, orientation, construction materials, as well as the local climate.
The energy performance of appliances (e.g., heating and cooling systems) are not measured in the star rating but are included in the NatHERS Whole of Home rating (out of 100).
Whole of Home
The Whole of Home rating is included in NatHERS assessments for a new home, major renovation or existing home, and complements the thermal star rating. It includes all major energy use and generation within the home including:
- hot water, heating and cooling systems
- pool and spa equipment
- lighting and plug in appliances
- solar energy generated onsite and battery storage.
The Whole of Home rating elevates the importance of energy performance in new builds and renovations, helping drive demand within industry for the skills needed to focus on energy performance.
Learn more about buying energy efficient appliances.
Getting an assessment
Using a NatHERS Accredited Assessor ensures a reliable energy rating. NatHERS assessors complete training and comply with professional quality assurance and a code of conduct.
To find a NatHERS Accredited Assessor, contact one of the Assessor Accrediting Organisations (AAO) for new homes, below:
- Australia Building Sustainability Association
- Design Matters National
- House Energy Raters Association
Example process
For a new home or major renovation, your assessor will review your new house plans and use special software to model and estimate a 'star rating' (out of 10) and a 'Whole of Home' rating (out of 100). Together these ratings tell you how energy efficient your home is and predict how much energy your home should use annually.
The assessor will then issue a NatHERS Certificate displaying both the 'star rating' and the 'Whole of Home' rating. This can be used to meet NCC energy efficiency regulations. Remember to always check specific state and territory building requirements.
Improving the energy efficiency of your home
Whether you are building a new home, undertaking a renovation, or just doing minor upgrades, you can improve the energy performance of your property.
The Your Home website is a free resource with top tips on energy efficiency. You can also order the Your Home book.
If you are interested in building a new home, Design For Place features a variety of free ‘ready-to-download’ house plans. The home plans feature sustainable design and construction techniques for a range of climate zones across Australia
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Understanding Climate Zones
Location has a significant effect on energy efficient design. Australia has diverse climates, from the hot tropics to the cooler, temperate regions of Tasmania, and everything in between. NatHERS software takes this into account when calculating an energy rating to ensure comparable ratings across different climate zones.
See NatHERS climate zones for more information.