The levels of acceptance of green roofs vary from country to country. Some countries have a bit of history and are simply a few steps ahead of the game, but in most cases, the factor that drives the number of green roofs found in a city is simply how much government support is offered in the form of subsidies and statutes requiring green roofs for Green Roof Policy adoption.
We’ll compare the support and regulation of green roofs in some of the world’s most advanced economies.
Green Roof Adoption In Canada
Canada has been growing its forest of green roofs over the years, but it’s not one of the leaders on the global stage. The growth here can be attributed mainly to municipal regulations rather than any overarching national policies.
One of the municipalities in Toronto has been a leader in this area, having passed a Green Roof bylaw in 2009, the first of its kind in North America. Recently adopted green roof bylaws require that over 20% (and up to 60%) of the roof area of all new commercial and industrial buildings over 2,000 m2 are to be green.
Incentives from the city have also been a great driver in their adoption. The Eco-Roof Incentive Program offers funding of up to $100,000 for green roof installation on both new and existing residential, industrial, commercial, and institutional buildings. Since 2009, the program has supported the installation of over 600 green roofs in the city, covering over 1.1 million m2.
Beyond Toronto, however, incentives are limited. One modest example is the City of Saskatoon, which offers a rebate on stormwater charges for buildings with green roofs; Port Coquitlam, B.C., expedites planning permits for projects incorporating green roofing. Vancouver’s Rain City Strategy has, without direct incentives, encouraged some notable projects like the Vancouver Public Library and the Vancouver Convention Centre; the latter hosts, at six acres, the largest green roof in Canada.
Singapore
Singapore stands out for its Skyrise Greenery Initiative, which has made it a global leader in green roof adoption. Given its status at the top of the charts of the most business-friendly countries, it’s no surprise that the city-state offers generous grants that cover up to 50 percent of installation costs for green roofs and vertical gardens. This financial, informational, and technical support has contributed to installing some 155 hectares (1.55 million m2) of green roofs in just a few years.
Property developers can also receive additional floor area allowances when incorporating green roofs into their projects, making them more attractive from a business perspective. These policies together have encouraged widespread adoption of green roofs, with numerous projects completed across the city-state.
Green Roof Policy In the United States
There’s no national mandate for green roof implementation in the United States, but some cities have developed effective regulations to support their adoption. Chicago’s Sustainable Development Policy, for one, requires certain buildings to meet sustainability standards, with green roofs as a key component. In addition to a mandate, the policy also offers developers density bonuses and expedited permits. The city also provides grants to promote green roofs, specifically targeting projects that address stormwater management and energy efficiency. As a result of this basket of incentives, Chicago has more green roofs than any other city in North America at 517,000 m2 (5,564,412 sq. ft.).
New York is another leader. The Green Roof Tax Abatement Program has been introduced to provide a property tax incentive on buildings with green roofs. The program builds on the city’s Local Laws 92 and 94, which mandate new buildings and additions, as well as full-roof replacements, to be partially covered with green roofs or solar panels.
Australia
Cities like Melbourne and Sydney are adopting policies to encourage green roofs, though the overall approach has been slower here than in many countries.
Melbourne’s Green Our City Strategic Action Plan offers grants and subsidies for businesses that implement green infrastructure and has helped the city realize a growing adoption of green roofs. This plan is aided by a joint initiative with the Victoria (state) government, the Green Our Rooftop project, which provides funding for education and research.
Sydney’s efforts center around its 2012 Green Roofs and Green Walls Policy, which so far appears to be limited to offering technical guidance. Such guidance helps remove some of the uncertainties around green roofs that may be experienced by owners and builders.
While many building improvements are under discussion in Australia, there appears to be little thought for green roofs at the federal government level, or even in the green building sector. A recent report by the Green Building Council and the Property Council offered a slew of recommendations for action at local, state, and federal levels, but green roofs were not mentioned.
France
While green roofs are evolving in cycles with mixed opinions, France has come a long way, being the country with the maximum number of initiatives, especially in Paris. Since 2015, Paris has also adopted a regulation that makes green roofs compulsory for new buildings covering more than 1,000 m2.
But France stole the show when the national government required green roofs or solar panels to be added to all new buildings in commercial zones across the country.
At the same time, these establishments are emphasised by different government-level subsidies to lower the cost of developing green roofs and facades and have accompanying enforcement mechanisms to ensure their wider application. One example of this is Paris’ Coproasis program, which provides financial assistance of up to €5,000 for the completion of technical studies and up to 80 percent (to €30,000) for the completion of a green facade.
Japan
Japan has implemented various policies to encourage green roofs, recognizing their potential to combat urban heat islands, improve air quality, and provide habitat for urban wildlife. Tokyo was ahead of its time when it established its Nature Conservation Ordinance in 2001. The law requires new buildings with a roof area of more than 1,000 m2 to incorporate vegetation (20 percent coverage for buildings 1,000 to 5,000 m2 and 25 percent for buildings above 5,000 m2). The ordinance has led to the creation of 180,000 m2 of new green roofs.
United Kingdom
In the UK, growth in green roof adoption is attributed to some key regulatory support, particularly in London. Though the London Plan’s Living Roofs and Walls Policy does not make green roofs mandatory for new development, it encourages them wherever feasible. By 2017, the city had around 1.5 million m2 of green roofs, some 42 percent of the nation’s total. If developers have not included green roofing without a strong justification, their planning approval can be challenged.
As well, the Community Infrastructure Levy has given localities from cities like Manchester, London, and Bristol a means of raising funds for green infrastructure projects, such as green roofs, by charging for new developments.
In addition to regulations
Japan offers financial incentives to promote green roof development. The government and local municipalities provide subsidies primarily for improving energy efficiency, which indirectly includes green roofs. One performance-based incentive is the Energy Conservation Promotion Project for Existing Buildings, which supports the renovation of office buildings. The government will cover one-third of the renovation costs under the program if the energy consumption of the building is reduced by 20 percent after the renovation.
Opting for green living roofs provides so many advantages that it can be better justified, from increasing the energy performance of a building to enhancing the biodiversity factor. Governments around the world realize this and so are cultivating the number of green roofs across their countries. While Canada has made significant strides, particularly in cities like Toronto and Vancouver, it still lags behind global leaders like Germany, Switzerland, and the Netherlands in terms of mandates and financial incentives.