The widely used NABERS rating scale has been extended to six stars, which means it now uses a similar scale to the Green Star rating used by the Green Building Council of Australia (GBCA). The extended rating will be given to buildings that exceed the existing five star rating by a significant margin.
Buildings currently rated at 5 stars that are performing at a 5.5 or 6 star level will be issued new certificates reflecting their new rating. This change does not affect other ratings, as the existing 0-5 star scale has not changed. New 6 star ratings are now available for NABERS energy and water ratings for offices, hotels and shopping centres. Other NABERS ratings will be extended by mid 2012. A 6 star rating is awarded for “market leading performance”, and represents a 50% reduction in greenhouse gas emissions or water use from a 5 star rating.
NABERS (National Australian Built Environment Rating System) has been in use for many years to rate the environmental performance of buildings on a 1 to 5 scale, in four key areas: energy consumption, water consumption, waste management and the built environment. They key difference between Green Star and NABERS has been that Green Star rates a building’s design and construction , while NABERS rates a building’s operation once constructed. Green Star is voluntary and run by the industry, NABERS is mandated in many cases (such as when office space changes hands) and run by the government (the NSW Office of Environment and Heritage on behalf of all Australia governments).
Both systems are in widespread use. They are unlikely to be amalgamated, because of their different purposes, but the tweaking of NABERS to an extra star does as least mean some level of alignment. It will still be the case that when someone talks of a “six star building” it will be necessary to ask whether it’s a six star Green Star or a six star NABERS, so we will probably start to hear terminology like “double six star”.
Environmental building standards in Australia remain a hodgepodge of competing and confusing systems operated by various levels of government and private industry. This is not about to change – but at least there is some agreement on the number of stars that represents peak performance.
