The French parliament recently passed a new law requiring all new commercial buildings to have plants or solar panels on their roofs.
This news will resonate with Australian property owners where green roofs are still their infancy. Issues around this topic will be covered in a strong line up at The Fifth Estate’s Urban Greening 2022 summit on 28 July, in collaboration with the Australian Institute of Landscape Architects, UTS and Living Future Institute.
While the proposal initiated by French environmental activists was for roofs to be completely covered by greenery, the government decided that to ease costs to businesses, roofs must be partially covered (to at least 30 per cent) with greenery instead of fully covered.
However, this is still a huge step toward more sustainable cities and infrastructure, the main benefits being to improve air and water quality as well as to increase greenhouse gas sequestration and combat pollution. Green roofs are also longer-lasting: the lifespan of green roofs is two to three times longer than traditional roofing materials.
Plants on roofs are known to reduce urban heat effect by providing shade, reducing the temperature of roof surfaces, and removing heat from the air.
The Green Building Council of Australia’s (GBCA) Living Wall and Green Roof Plants for Australia report by the Australian Government Rural Industries Research and Development Corporation in 2012 found that green roofs and living walls in the built environment “offer significant environmental, economic and social benefits” – so why are there so few green roof buildings in Australia?
There is some progress in Australia, with some green roofs in Sydney and Melbourne having the Green Our Rooftop project as a key part of the Green Our City Strategic Action Plan towards more green infrastructure. There are no mandates on green roofs.
In the City of Melbourne there are currently about 40 green roofs covering five hectares, which compared to other cities is not much. Toronto has around 500 green roofs and Munich has 300 hectares of green roofs.
The GBCA report states: “Green roofs and living walls in the built environment offer very significant triple bottom line benefits. These benefits include ameliorating urban heat island effects, reducing energy demands and attendant CO2 emissions (such as from airconditioning) as well as improving the wellbeing and productivity of citizens, and providing habitat for micro- and macro-organisms.
“Although novel in Australia, green roofs and living walls are becoming increasingly widespread throughout Europe, Asia and North America.”
France’s rejection of outdated traditional roofs and embracing of green roofs in the Climate and Resilience Act demonstrates the powerful transformation that can occur when government’s embrace ecology in all aspects of society: in urban planning, public services, consumption patterns, education, and travel.
Paris has also opted to ban cars in the city centre from 2024 to encourage use of public transport, bicycles and foot traffic.
Exceptions to the rule include public vehicles, residents who live in the included precincts, delivery drivers, and those accessing services such as shopping centres.
The move is expected to remove 50 per cent of cars off the road – which Bloomberg estimates amounts to 100,000 cars per day. The city also added more than 160 kilometres of bike lanes during the pandemic.
Some countries in Europe (including Belgium, the Netherlands, and the UK) have begun offering tax incentives that essentially pay citizens to cycle to work instead of using a car.