Green Star-rated buildings emit around a third of the greenhouse gas emissions and use a third of the electricity when compared with the average Australian building, a new report finds.

The Value of Green Star: A decade of environmental benefits, released by the Green Building Council of Australia (GBCA) today, analyses data from 428 Green Star-certified buildings and fitouts and compares it to the ‘average’ Australian building and minimum practice benchmarks.

“Hundreds of buildings around Australia, from offices to factories, shopping centres to schools, libraries to hospitals, have achieved Green Star ratings,” explains Romilly Madew, the GBCA’s Chief Executive.

“This is the first time we’ve quantified Green Star’s overall impact on Australia’s built environment. This new report complements the large number of case studies and substantial anecdotal evidence of Green Star’s transformative effect on sustainability at the individual building level,” Ms Madew says.

The report examines the impact of Green Star on greenhouse gas emissions, operational energy and water consumption, and construction and demolition waste. The findings include:

Energy and greenhouse gas emissions

• On average, Green Star-certified buildings produce 62 per cent fewer greenhouse gas emissions and use 66 per cent less electricity than average Australian buildings.
• They also produce 45 per cent fewer greenhouse gas emissions and consume 50 per cent less electricity than new buildings designed and constructed to meet the construction code requirements.
• Taken together, the 428 Green Star buildings in the study have reduced electricity consumption by 580,000 megawatt hours or 2,088,00 gigajoules per year. This reduction is equivalent to five per cent of the Hazelwood Power Plant’s total annual output, or the same as 76,000 average households’ annual electricity use.
• The cumulative greenhouse gas savings from the Green Star-rated buildings surveyed, when compared to the average, totals 625,000 tonnes of carbon dioxide a year. That’s equivalent to taking 172,000 cars off our roads.

Water

• Green Star buildings use 51 per cent less potable water than average buildings.
• That saving – which amounts to 3,300,000 kilolitres of potable water a year – is enough to service 18,000 households or fill 1,320 Olympic swimming pools.
• These water-saving measures deliver significant payoffs, from cost savings to habitat conservation, and from reduced pressure on infrastructure to energy conservation, as improved water efficiency reduces the need for water pumping, delivery and waste water treatment.

Waste

• The 2010 National Waste Report found that construction and demolition waste accounts for 38 per cent of the total waste sent to landfill.
• The average new construction project has a 58 per cent recycling rate. In comparison, Green Star – As Built certified buildings (those projects that achieve a rating for completed construction) recycled 96 per cent of their construction and demolition waste.
• In total, 37,600 truckloads of construction and demolition waste from Green Star-rated projects – 564,000 tonnes – have been diverted from landfill due to good waste management practices.

“Our research also finds that the higher the Green Star rating, the greater the environmental savings across the four key areas of greenhouse gas emissions, energy use, water consumption, and construction and demolition waste,” Ms Madew says.

“This report confirms what we’ve been saying for a decade – Green Star buildings are slashing greenhouse gas emissions, making significant savings on energy and water consumption and costs, and preventing truckloads of waste to landfill.

“The savings that Green Star is delivering for the built environment – financial, social and environmental – are just too good to ignore,” Ms Madew concludes.

Download ‘The Value of Green Star: A decade of environmental benefits‘.