A House Energy Rating is an index of energy efficiency for residential homes in Australia.
The Australian Building Codes Board introduced energy efficiency measures for houses into the Building Code of Australia (BCA) on 1 January 2003. It has been adopted by all Australian states and territories which did not already have an equivalent system in place. Victoria and South Australia have gone beyond the standard, and mandated a 5-star rating, instead of 4-stars. During 2006, requirements for 5-star energy ratings were introduced for new homes through the BCA in Western Australia and the Australian Capital Territory. As of mid 2007 Tasmania, Queensland and the Northern Territory have not adopted 5 star requirements for new homes. New South Wales has not adopted requirements under the BCA and operates its own Building Sustainability Index or BASIX.

Star ratings

A 5-Star rating indicates that the house has achieved a high level of thermal energy performance, and will require minimum levels of heating and cooling to be comfortable in winter and summer. Houses which achieve a 5 star rating, compared to the average 2 star home, should be more comfortable to live in, have lower energy bills, and costs to install heating and cooling equipment should also be lower.

Energy assessments take into account different climatic conditions in different parts of the country and are benchmarked according to average household energy consumption particular to a given climatic region.

The house energy rating does not currently include the efficiency of any appliances fitted or used within the house.

Software

For calculating the efficiency of a house, the software tools used are NatHERS (the Nationwide House Energy Rating scheme/software, which is to be replaced by the CSIRO's AccuRate), BERS and FirstRate. Which software packages and versions are approved varies from state to state.

While FirstRate only gives ratings up to 6, AccuRate will report up to 10 stars. http://www.greenhouse.gov.au/yourhome/technical/fs110.htm

Australian state-based initiatives

ACT House Energy Rating Scheme (ACTHERS) http://www.actpla.act.gov.au/design-guide/acthers/, requires new or previously lived in residential homes to have an Energy Efficiency Rating (EER) Statement, prepared by an accredited ACTHERS assessor, if they are to be sold. As of the February 2006, the required software used in assessment is FirstRate, Version 3.1 or Version 4. http://www.actpla.act.gov.au/design-guide/acthers/eer_sell.htm

In Victoria, since July 2004, all new homes are required to achieve a 5 Star rating. http://www.sustainable-energy.vic.gov.au/seinfo/your-home/Home%20building%20and%20design/energy%20rating%20and%205%20star/index.asp A 5 star rating can be achieved for the building fabric alone, or through a 4-star rating (based on building fabric) combined either a rain water tank connected to all flush toilets or a solar hot water system. There are two approved software packages: FirstRate and NatHERS.

In South Australia, all new homes (and alterations to existing homes) are required to achieve a 5 star rating. This requirement was introduced on 1 May 2006. http://planning.sa.gov.au/index.cfm?objectid=1F05999B-96B8-CC2B-691B6F3A96013410