A report by the Green Building Council of Australia (GBCA) has found buildings rated by Green Star emit a third of the greenhouse gas emissions compared to average Australian buildings.
The Value of Green Star: A decade of environmental benefits report also revealed Green Star buildings use a third of electricity compared to average Australian buildings.
The Green Building Council of Australia report analysed 428 Green Star certified buildings and fitouts and compared them to average Australian buildings.
The study aimed to quantify the overall impact of the Green Star rating system on greenhouse gas emissions, operational energy, water consumption and construction and demolition waste.
“Hundreds of buildings around Australia, from offices to factories, shopping centres to schools, libraries to hospitals, have achieved Green Star ratings,” said 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.”
According to the report, Green Star buildings:
• produce 62% fewer greenhouse gas emissions and 66% less electricity compared to average Australian buildings
• produce 45% fewer greenhouse gas emissions and 50% less electricity than new buildings meeting construction code requirements
• use 51% less potable water than average buildings, saving 3,300,000 kilolitres of potable water per year
• recycle 96% of construction and demolition waste for Green Star – As Built buildings, compared to 58% on new construction
Of the 428 buildings analysed for the report, the Green Building Council of Australia found electricity consumption dropped by 580,000 megawatts per year, equivalent to the electricity use of 76,000 homes per year.
The buildings have also saved 625,000 tonnes of carbon dioxide per year compared to average buildings.
A total of 564,000 truckloads of construction and demolition waste has also been saved in Green Star-rated projects 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 said.
“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.”
The study also found the higher the Green Star rating (4 stars, 5 stars and 6 stars), the greater the environmental benefits of the building in terms of greenhouse gas emissions, energy use, water consumption and construction and demolition waste.
Green Star was introduced in 2003, with more than 5.5 million sqm of building area now certified by the rating system.
The majority of the 428 buildings analysed by the Green Building Council of Australia study were office buildings (249), followed by office interiors (95). Other buildings analysed included education, healthcare, industrial, multi-unit residential, retail and public buildings.
A total of 54 of the buildings studied were rated 6 stars, with 201 rated 5 stars and 173 rated 4 stars.
The methodology and findings of the report have been peer reviewed by independent consulting firm Net Balance.