(This is an article I wrote for UrbanToronto)
Toronto’s City Planning division has produced a new resource called Guidelines for Biodiverse Green Roofs, detailing best practices for promoting biodiversity on green roofs in Toronto. Green roofs provide insulation for buildings, improve air quality and the quality of water runoff, and cut down on the urban heat-island effect. New commercial, institutional and residential development with a minimum Gross Floor Area of 2,000m2 in Toronto require a portion of the roofs to be green. Starting April 30, 2012, the Green Roof Bylaw will require to same for new industrial development.
Though it may be of interest to residents, the document is primarily intended to help architects and landscape architects integrate biodiversity into their designs by providing strategies for creating appropriate ecozones alongside natural heritage features. The Guidelines give designers: a comprehensive list of plants suitable for green roofs that encourage biodiversity; recommended growing medium depths and composition; and, ideas for creating habitat aimed at specific species. They are to be used in conjunction with the existing Toronto Green Roof Construction Standard Supplementary Guidelines.
Seeing green roofs as part of the larger urban ecosystem and recognizing their ability to greatly improve the quality of life in the city, Toronto implemented its Green Roof Bylaw in 2012. “The Green Roof Bylaw and the Guidelines for Biodiverse Green Roofs are both the first of their kind from a government in North America,” said Steven Peck, President of Green Roofs for Healthy Cities, a not-for-profit association promoting the green roof and wall industry in North America.
Chief Planner for the City of Toronto Jennifer Keesmaat also applauded the new Guidelines, saying they will enhance the impact of the bylaw by implementing some of the policies contained in the Official Plan. “Our Official Plan recognizes the importance of protecting, restoring and enhancing the health and integrity of the natural ecosystem and supporting biodiversity.”