Toronto’s example of green roofs

In February 2006, the city government of Toronto, Ontario, approved “Making Green Roofs Happen,” a strategy that commits to installing green roofs on new and existing buildings. Among other recommendations, the policy calls for financial incentives for privately owned green roofs in the city.

The goal is to reap significant energy, air-quality, and climate-changing benefits of green roofs.

Toronto had commissioned a multidisciplinary green-roof benefits study prior to the February actions. Researchers found that 8% coverage of existing Toronto rooftops with extensive green roofs would generate more than $300 million in initial cost savings in areas such as storm water management, sewer overflow reduction, energy savings in buildings, and temperature reductions in the urban heat island.

Specific operational cost savings for the city from this level of cove age were estimated at approximately $40 million per year.

Ron Bygness, editor of Geosynthetics (formerly GFR), and Green Roofs for Healthy Cities, contributed to this article.