What does a NatHERS assessment include?

A NatHERS assessment includes NatHERS Accredited Software that is used to determine an energy efficiency rating. This is completed by a NatHERS accredited assessor who can be verified by the NatHERS logo on the Universal Certificate. A NatHERS Universal Certificate will provide information regarding the key design features of the dwelling, the building materials, and the scope used to generate the dwelling’s star rating.

Energy Rating

An Energy or Thermal Efficiency star rating is an accurate indicator as to how much heating or cooling is necessary to keep your development comfortable. The energy rating generated by an accredited NatHERS assessor using licensed software indicates a dwelling’s efficiency in preserving energy. Please note, it does not indicate the dwelling’s actual consumption of energy as that depends upon appliances installed and the way in which they are used (only assessable after occupancy). By improving your energy rating you will require less energy to keep your dwelling comfortable and therefore provide lower energy expenses as well as a much healthier environment.


The possible 0 to 10 stars, is a scale that indicates the energy efficiency of a dwelling. If a dwelling is rated 0 stars then it offers no insulation from the outside temperature. For example, if it is 20 degrees outside it will be 30 degrees inside. Whereas a 10-star dwelling is able to maintain a comfortable inside temperature all year round no matter what the outside temperature. Hence, the more stars a dwelling has the less energy it consumes, therefore reducing energy expenses.

Do appliances such as, air-conditioners, etc. affect star ratings?

Generally, no as NatHERS energy ratings are based on how well designed the dwelling will be. Appliances added to the building and are likely to be changed in the future are not taken into consideration.

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Who can perform NatHERS?
How are NatHERS star ratings assessed?

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What is NatHERS?
When is NatHERS required?

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