Today’s green star buildings will face the test of time


Buildings that shine today can fall behind in tomorrow’s star ratings urban landscape, writes Miriam Hechtman.

If you want a building to have enough green credibility to rate a mention in the annual report or in staff newsletters, you have to deal with two, interacting sets of ratings – one for the building and the other for its operation.

In addition, the rating targets are always moving, so a six-star building opening its doors today may not rate six stars a few years down the track.

The first tool is the green star system for buildings set up by the Green Building Council of Australia (GBCA). The other is the National Australian Built Environment Rating System (NABERS) that measures the energy, waste, water and indoor environment performance of a building.

“These are the two principal tools used in the industry,” says the Property Council of Australia’s chief executive, Peter Verwer, “and the difference between them is that NABERS focuses on actual consumption and green star deals more with the design of the building and its attributes. So the design of the pipe is green star and what runs through the pipe is NABERS.”

GBCA chief executive Romilly Madew says that when the green star system was launched nationally in 2002, the council intended “to create a framework for the industry so they knew how to build green, and also for advocacy, so to identify barriers and work with the government to remove them”.

The green star rating system comprises nine main categories that are integrated into a variety of tools that take into account the project’s site selection, design, construction and maintenance. These categories include management, indoor environment quality (IEQ), energy, transport, water, materials, land use and ecology, emissions and innovation. Each category is allocated credits that can be awarded for achieving certain environmental objectives.

Green star also incorporates NABERS in its energy category and is a compulsory part of green star. In the green star office tool, for example, “the only way to achieve a green star rating is you also need to achieve a NABERS energy rating,” Madew says.

The NABERS energy tool, launched in 1998 as the Australian Building Greenhouse Rating (ABGR), was developed by the NSW government and adopted nationally in 2000. The NSW Department of Environment and Climate Change (DECC) manages NABERS on behalf of other state and commonwealth governments. The Department of Environment and Climate Change’s manager of built environment, Matthew Clark, says: “A NABERS rating is a measure of the actual environmental impact of a building.

“It is based on the energy or water consumed, waste generated or the quality of the indoor environment. Sophisticated energy modelling software is able to estimate the future energy use of a building at the design stage. This estimate can be used to predict the future NABERS energy rating of the building.”

NABERS rates buildings on a scale from one to five stars. Ratings benchmark a building against current market performance, and two and a half stars represent market average performance. A five-star rating demonstrates best practice as well as indicating that the structure is using 50 per cent to 60 per cent less energy than an average building. A one-star rating building signals performance well below average market practice.

GBCA is directly responding to industry demand, says Madew, and Australia has had faster growth in this area than any other country. “The reason being the industry looked at themselves and said there’s got to be a point of difference between us and our competitors. Our tenants are demanding it, especially all federal, state and local governments. They are demanding green interiors and green tenancies and also corporate social responsibility has taken off.”

The last two years have been particularly busy for GBCA. Staff numbers have tripled, and membership has grown from 200 to about 600. There are now 14 six-star rated buildings in Australia, which is the highest rating awarded, and there are 32 four-star and 41 five-star buildings.

Madew says there will never be a seven-star rated building but rather an updated version of six star. “We keep increasing our standard benchmark as the market gets better so we just make a higher level. The market know this. They know that a building that may have got six stars three years ago is going to be very different to a building that gets six stars today.” GBCA is exploring how buildings that have already been awarded a rating can have their accreditation refreshed.

In 2008, a total of 28 buildings earned a NABERS five-star rating and since the rating was introduced, there have been a total of 58 five-star rated buildings. And 40 per cent of the national office market (by area) has rated its building performance with NABERS energy “We have seen significant change in this market, with buildings demonstrating a 10 per cent reduction in energy use and 20 per cent cut in water use,” says Clark.

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