ENERGY RATING is an index of a building’s thermal performance (i.e. heating and cooling requirements) for residential homes in Australia.
House energy rating through the Nationwide House Energy Rating Scheme (NatHERS) uses computer simulations to assess the potential thermal comfort of Australian homes on a scale of zero to 10 stars. The more stars, the less likely the occupants need cooling or heating to stay comfortable.
The result is expressed as MJ/m² per annum required maintaining the house at a comfortable temperature. This is broken up into a heating load (how much energy it takes to heat the house) and a cooling load (how much energy it takes to cool the house).
The result is correlated with the climate zone and used to determine the star rating of the house.
(69 Climate zones in Australia, 23 in Western Australia and 4 Metropolitan)
What is rated?
The rating depends on:
- the layout of the home
- the construction of its roof, walls, windows and floor
- the orientation of windows and shading to the sun’s path and local breezes
- how well these suit the local climate.
Energy consumption by hot water systems, lights or household appliances is not part of the rating.
What the stars mean
- Zero stars means the building shell does practically nothing to reduce the discomfort of hot or cold weather.
- A 5 star rating indicates good, but not outstanding, thermal performance.
- Occupants of a 10 star home are unlikely to need any artificial cooling or heating.
For more information on how Energy Rating will affect the energy efficiency of your house, or you would like to know more about the service Sustainability WA provide including an Energy Rating or Energy Efficiency certification for your project please contact us here or phone 08 9537 2000
Other terms sometimes used to describe an energy rating includes: Energy Star, Energy Audit, Energy Ratings, Energy Efficiency Certificate, Energy Assessment, HERS, BER or EPC.
Sustainability WA can help you with them all!