Toronto Green Roof Bylaw

The Toronto Green Roof Bylaw is a municipal law adopted by Toronto City Council on May 25-26, 2009. It requires green roofs on many new developments above a size threshold. The bylaw is part of Chapter 492 of the Toronto Municipal Code, which also contains the Toronto Green Roof Construction Standard.

Who it applies to

• Residential, commercial and institutional development with a gross floor area of 2,000 m² (about 21,500 sq ft) or more. Residential buildings under six storeys or 20 m (about 66 ft) in height are exempt.
• Industrial buildings (new buildings or additions) with a gross floor area of 2,000 m² or more.

Required coverage

For residential, commercial and institutional buildings, the required share of "available roof space" rises with gross floor area:

• 2,000-4,999 m²: 20 percent
• 5,000-9,999 m²: 30 percent
• 10,000-14,999 m²: 40 percent
• 15,000-19,999 m²: 50 percent
• 20,000 m² or more: 60 percent

Industrial buildings may either green the lesser of 10 percent of available roof space or 2,000 m², or use cool roofing materials on all available roof space and meet stormwater performance measures.

Cash in lieu

With the Chief Planner's approval, an applicant can provide less green roof than required by paying $200 per square metre of shortfall. These payments go to the City's Eco-Roof Incentive Program.

Construction Standard

All green roofs in Toronto must meet the Toronto Green Roof Construction Standard, which covers structural loads, fire safety, waterproofing, drainage, plant selection, irrigation and maintenance.

Significance

The bylaw is frequently cited as a model by other cities. It combines a size-based mandate, a cool roof alternative for industrial buildings, a payment option, and incentives for retrofits.