Green roofs and green walls will grow from a $5.3 billion market in 2011 into a $7.7 billion market in 2017, driven by mandates and incentives in cities worldwide, according to Lux Research. But while installations will increase 70 percent to 204 million square meters, costs and lack of validation will limit their rise.
Green roofs will account for $7 billion of the 2017 market, presenting a $2 billion opportunity to suppliers of polymeric materials such as geosynthetic fabrics and waterproof membranes, according to Building-Integrated Vegetation: Redefining the Landscape or Chasing a Mirage?
Green walls, meanwhile, will swell to a $680 million market, using $200 million worth of materials such as self-supporting polyurethane foam growth media.
Rapid urbanization over the past 50 years has caused air pollution, urban heat-island effects and loss of green spaces. To combat these and other environmental issues, cities such as Copenhagen, London, Singapore and Chicago have issued mandates or incentives for vegetated roofs to reduce storm-water volume, clean air pollutants, reduce the heat-island effect and sequester carbon dioxide.
However, it’s difficult to monetize the environmental benefits of green roofs and walls, and some wonder if building-integrated vegetation is merely a “green curiosity,” says Aditya Ranade, Lux Research senior analyst and the lead author of the report.
While green roofs and walls do offer a multitude of environmental benefits, they face obstacles to widespread implementation, the report says. Installed cost — $300/m2 to $500/m2 for green roofs and $900/m2 to $1,100/m2 for green walls — is far higher than alternatives.
And while adoption is driven by a handful of cities in the developed world, growth in the developing world will depend on the global economic market.
The report forecasts more building material suppliers will develop building-integrated vegetation materials and create special grades of waterproof membranes and geosynthetic fabrics suited for building-integrated vegetation. Products will improve as the market becomes more mainstream and more performance standards are established.
In other green roof news, new research funded by the UK’s Royal Horticultural Society and Portugal’s Fundacao para a Ciencia e a Tecnologia found green-roof plants other than sedums may help cool air temperatures more effectively, Energy Manager Today reports. The study looked at the possibility of using different plants — sedum, Stachys byzantina, Hedera hibernica and Bergenia cordifolia — for green roofs. Sedum is currently the most popular, according to RHS.
Photo Credit: Green Roof Blocks