The Australian Greenhouse Rating Scheme: Performance Rating Commercial Buildings

摘要

The Australian Building Greenhouse Rating Scheme is an initiative of the Sustainable Energy Development Authority of New South Wales. The rating provides a simple performance based assessment of office buildings in operation, using a five star rating scheme, and has three options for the coverage of what is being rated: tenancy, base building and whole building. This paper describes the rating scheme in overview and summarises a number of the lessons that have been learnt through its development and operation since 1999. The underlying principle of the rating scheme is to facilitate the creation of a market for efficient buildings by providing simple, readily understood information about building energy efficiency. This differentiates it from the vast majority of previous work in commercial building ratings internationally, which have tended to focus on providing tools and rules to the design industry rather than a measure of actual performance. The primary information used to determine the rating scale is the statistical distribution of energy use of office building in Australia. This ensures that the rating is demonstrably linked to reality. Correction factors are applied to cope with hours of use, occupant equipment density and climate so that individual buildings are not discriminated for or against by the parameters of the building's necessary work functions. A five star building generally equates with best practice (e.g. a well-designed naturally ventilated building) while one star normally indicates major flaws in building design, maintenance and operation. The scheme was launched in NSW in 1999 and has subsequently has been extended to the whole of Australia. The scheme has achieved significant impacts and has generated a great deal of interest and activity in the property industry. A new development has been the extension of the scheme to a "Commitment Rating" which allows developers of new buildings to commit to the achievement of a given rating by a new building. The operation of the scheme has demonstrated a number of interesting issues regarding the achievement of energy efficiency in commercial buildings, and the limitations of existing processes and industry infrastructures to deliver efficient outcomes. These will be briefly overviewed in the paper. It is expected that there will be a long learning curve before the design and construction industry fully comes to terms with the issues surrounding the delivery of performance rather than merely design.