Transforming Melbourne's skyline: Plan for green roofs across the city
The roof of the austere concrete government office 1 Treasury Place will be transformed into a lush landscapeto demonstrate how existing buildings can be retrofitted with green roofs to help Melbourne adapt to climate change.
As part of the project, research will also be conducted into why Australian cities are lagging behind those in Europe and North America when it comes to installing green roofs, despite the environmental and social benefits.
Green roofs and vertical greening reduce greenhouse gas emissions, provide cooling and reduce stormwater runoff which decreases flash flooding.
The $2.7 million demonstration roof, a joint initiative between the state government and Melbourne City Council, is expected to be completed by June 2020.
"Establishing more green roofs across Melbourne is a great way to help the environment and reduce building operating costs, while also improving the health and wellbeing of those living and working in the city," Victorian Environment Minister Lily D’Ambrosio said.
Ms D’Ambrosio said it was expected there would be some reduction in air conditioning costs and energy use at 1 Treasury Place, because green roofs act like insulation.
The Melbourne City Council area (which stretches from the CBD into Carlton, Docklands and Parkville) only has about 40 green roofs covering five hectares of space.
That is despite rooftops across the inner-city area making up 880 hectares, more than five times the size of Royal Park.
This compares to Toronto in Canada which has about 500 green roofs and Munich which has 300 hectares of green roofs.
In 2009, Toronto was the first city in North America to adopt a bylaw to require and govern the construction of green roofs.
Former Melbourne Lord Mayor Robert Doyle said in 2015 he did not support mandatory building rules to ensure that roof space was used to help green and cool the city.
City of Melbourne planning chair Councillor Nicholas Reece said the 1 Treasury Place green roof was a great example of the council and state government working together to tackle climate change.
He said the council also offered seed funding to encourage developers to install green roofs but had not introduced mandatory policies such as those in Toronto, Munich, Denver, San Francisco and - most recently - New York City.
"I think we need to keep a close watch on how current interventions are going," Cr Reece said.
"If they are not delivering to the same degree as other cities we like to compare ourselves to, then we need to revisit and think about further interventions."
Associate Professor Nicholas Williams from the University of Melbourne will lead a team that will research the barriers to green roof take-up in Australia, what plant species are best suited, maintenance and irrigation requirements and costs and which designs have the most wellbeing benefits.
He said the design of the rooftop was yet to be finalised but would include a range of exotic and native species, wildflowers, medium sized shrubs and grasses.
"Green roofs bring biodiversity back into cities - native animals are attracted onto roofs," Dr Williams said.
He said there were also a range of social and economic benefits, including an improvement in productivity when people were able to look at green roofs.
The Treasury Place building was constructed in the 1960s. It was designed by architect Barry Patten from Yuncken Freeman Architects, who won a competition that required entries to express “soaring wonderment”.
However Patten ignored this direction, arguing that a skyscraper "would destroy probably Melbourne’s best vista".