The minimum star energy efficiency rating requirements for residential homes and commercial properties in Australia is changing, and software that measures the thermal performance of buildings is being improved.  

From 1 May 2009, all new buildings and building extensions must meet a specified level of energy efficiency according to the Building Code of Australia (BCA). The minimum energy efficiency is increasing to the equivalent of a 5 star rating, and will affect Queensland the most because its previous minimum rating requirement was 3.5 stars.  

COLORBOND steel with Thermatech technology supplied by BlueScope Steel reflects more heat on hot days, resulting in a cooler roof and a more comfortable home when used in conjunction with standard levels of insulation. In Queensland’s hot climate, COLORBOND steel roofing with Thermatech technology can decrease a building’s yearly annual heating and cooling energy consumption by up to 20%. This reduces the need for air conditioning in summer, resulting in smaller energy bills and few greenhouse gases being emitted.  

All 20 colours in the standard COLORBOND steel range feature Thermatech solar reflectance technology. The star rating refers to the energy efficiency of a building, and takes into account factors such as how much energy is needed to heat and cool the building to a comfortable level all year round. The better the thermal performance of a building, the higher the star rating. Buildings that remain thermally comfortable without the need for additional heating and cooling achieve a higher star rating.  

Improvements have been made to the software used to determine the star rating of a building. Second generation versions of AccuRate, FirstRate5 and BERS Pro have been upgraded to take into account more aspects of the building, including consideration of higher solar reflectance of roofing materials.  

Commercial & Industrial Market Manager of BlueScope Steel, Garth Weston, said that introduction of the new star rating and improved software means that assessing the thermal performance of a building is going to require consideration of more of a building’s components.  

It was announced by the Council of Australian Governments (COAG) in early May this year that a minimum 6 star energy efficiency rating for all residential homes and commercial properties built after May 2011 will be required. The Government has agreed to revise its requirements and implement the 6 stars standard in order to promote the construction of  more energy efficient buildings and reduced carbon emissions.