Executive summary: Since the launch of the Green Star rating system in 2003, hundreds of buildings around Australia have been independently certified for their sustainable design and construction using Green Star rating tools.A large amount of evidence that illustrates the transformative effect of Green Star on sustainability at the individual building level has been collected to date. However before now, no comprehensive quantitative research has been conducted into the overall impact that Green Star has had on Australia's built environment.
In late 2012, the Green Building Council of Australia (GBCA) conducted a quantitative research study using data from certified projects to quantify the overall impact of Green Star on greenhouse gas emissions, operational energy usage, operational water consumption and construction and demolition waste.
The study utilised data from 428 Green Star certified projects' submissions and compared this data to standard minimum practice benchmarks. The majority of data included in Green Star submissions are estimations of operational performance. There is evidence that confirms such estimates are representative of actual performance. Despite this, it is important to note that many of this study's findings are derived from estimated performance.
- On average, Green Star certified buildings produce 62% fewer greenhouse gas emissions than average Australian buildings.
- On average, Green Star certified buildings produce 45% fewer greenhouse gas emissions than if they had been built to meet minimum industry requirements.
- On average, Green Star certified buildings use 66% less electricity than average Australian buildings.
- On average, Green Star certified buildings use 50% less electricity than if they had been built to meet minimum industry requirements.
- On average, Green Star buildings use 51% less potable water than average buildings.
- The cumulative savings in green house gas emissions from Green Star certified buildings equates to 172,000 cars removed from our roads, when compared to average Australian building ␣ that is 625,000 tonnes CO2 per annum.
- Green Star certified buildings save enough potable water to fill more than 1,300 Olympic swimming pools every year, that is, over 3,300,000 kL per annum.
- On average, Green Star As Built certified buildings recycled 96% of their construction and demolition waste.
- Since Green Star's introduction to the market in 2003, more than 5.5 million square metres of building area have been Green Star certified.
- Green Star certified buildings save the equivalent of 76,000 average households' electricity use annually.
- 37,600 truckloads of construction and demolition waste has been diverted from landfill due to good waste management practices when constructing Green Star certified buildings.
- The higher the Green Star certified rating of a building (4, 5 or 6 star) the greater the environmental savings across all key areas ␣ greenhouse gas emissions, energy use, water consumption, and construction and demolition waste.