House energy ratings
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.
What is rated?
A dwelling can be rated before or after it is built. 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.
Installing wall insulation
for information about
energy efficient design
Energy consumption by hot water systems, lights or household appliances is not part of the rating because those fittings are usually replaced several times during the life of the building.
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.
- More about star ratings...
Houses built in 1990 averaged about 1 star on the NatHERS scale. Before the introduction of national energy efficiency regulations for houses in 2003, less than one per cent of Australian houses achieved 5 stars.
Many well designed houses are now being built above 6 stars or more, and examples are available on the Your Home website at: www.yourhome.gov.au