Green Roofs: The Sky’s the Limit in Toronto

Abstract

In a 2012 speech, United Nations Secretary-General Ban Ki-moon called for the world’s mayors and local governments to engage in the creation of sustainability policy for cities by stating that “Our struggle for global sustainability will be won or lost in cities.” The application of green roofs at a city-wide scale improves urban sustainability and is a function of local government policy creation. The City of Toronto introduced a municipal green roof by-law to increase the amount of green roof space to primarily mitigate the urban heat island effect and decrease the amount of stormwater runoff. However, there are many benefits to green roofs beyond these two functions. This research presentation uses the City of Toronto as a case study to understand the role of policy in green roof implementation at a city-wide scale before analyzing the benefits of green roofs for cities from an architectural, ecological, and planning perspective. In an increasingly urbanized world, transforming densely populated urban agglomerations into sustainable spaces is a critical component to mitigating the effects of climate change. Green roofs increase the sustainability of urban areas, and with careful consideration of the negative aspects, help create healthier cities. The City of Toronto’s green roof bylaw as a case study is a useful guide for cities wishing to create evidence-based green roof policies which contribute to healthier cities and a more sustainable global urban future.