Environment Minister Stéphane Dion should be congratulated for his suggestion to add greenery to Ottawa by requiring all new federal government buildings to have gardens on their roof.
The suggestion is another heartening sign that the federal government wants to safeguard the environment.
Earlier this year, $40,000 was invested to study potential policies and programs for green roofs.
The money will come from a $250-million federal endowment to the Federation of Canadian Municipalities.
There is already strong evidence that vegetation on roofs improves the environment.
It helps the air quality because plants absorb pollutants such as carbon dioxide. It also delays run-off into sewage systems by absorbing water with its roots, which reduces the potential of a sewage overflow.
Garden roofs can reduce urban heat, which is caused by a high concentration of heat-absorbing dark surfaces.
There are compelling economic reasons to plant gardens on roofs, as well. They reduce the amount of energy needed to heat or cool buildings.
Rooftop gardens provide shade and insulation as well as protect roofs from exposure to harmful ultraviolet (UV) radiation.
The initiative is particularly important to Centretown because Dion also wants to plant gardens on top of existing federal government buildings.
It sets a good example and encourages Ottawa businesses and other communities to establish their own roof gardens.
The federal government already offers incentives, such as providing funding to organizations who make their buildings more energy-efficient, including those who choose to establish a rooftop garden as one such initiative.
Green roofs have become popular in Europe in the past decade. More than 10 per cent of flat roofs in Germany, for example, have gardens. More than 40 per cent of German cities have programs to promote roof gardens, including financial support and regulations.
Switzerland recently passed a law requiring designs of new buildings to relocate the green space covered by the building to their roofs. Even 20 per cent of every existing building rooftop must be covered by greenery.
And by aggressively encouraging the establishment of rooftop gardens, Singapore has transformed their sea of eye-sore skyscrapers into a land of leaves.
Canadians are catching on. The Vancouver Convention Centre opening in 2008 will have the largest rooftop garden in the country covering the equivalent of four city blocks.
The idea of a roof garden goes back to the Hanging Gardens of Babylon. And while Dion’s plan isn’t as elaborate, it’s a great idea that will improve the quality of life in Ottawa.
— Trevor Sinker