In 2009, Toronto was the first city in North America to adopt a bylaw to require and govern the construction of green roofs. The Green Roof Bylaw sets out a graduated green roof requirement for new development or additions that are greater than 2,000 m² in gross floor area. The requirement ranges from 20-60% of the Available Roof Space of a building.
Green Roofs are required on:
The green roof coverage requirement is graduated, depending on the size of the building. The table below shows how the requirement ranges from 20-60 per cent of Available Roof Space for commercial, institutional and residential development.
| Gross Floor Area * (Size of Building) |
Coverage of Available Roof Space (Size of Green Roof) |
|---|---|
| 2,000-4,999 m² | 20% |
| 5,000-9,999 m² | 30% |
| 10,000-14,999 m² | 40% |
| 15,000-19,999 m² | 50% |
| 20,000 m² or greater | 60% |
* Note: Residential buildings less than 6 storeys or 20 m in height are exempt from being required to have a Green Roof.
Available Roof Space is defined in the Green Roof Bylaw as the total roof area minus the following:
Only the roof ares identified in the Bylaw are permitted to be excluded from the calculation of Available Roof Space.
The Green Roof Bylaw applies to new building permit applications for industrial buildings or additions to industrial buildings where the Gross Floor area is 2,000 m² or greater. Under the Green Roof Bylaw, Industrial buildings are required to provide one of the following:
Where the Site Plan Approval is not required, the first 5 mm from each rainfall or 50% of annual rainfall volume falling on the roof is retained or collected for re-use at least through systems that incorporate roof surfaces.
Whether constructing a green roof voluntarily, or as required by the Green Roof Bylaw, all green roofs in the City of Toronto, at a minimum, must conform to the Toronto Green Roof Construction Standard. The Standard can be found in Article IV of the Green Roof Bylaw (Municipal Code Chapter 492, Green Roofs). It complements the other sections of the Green Roof Bylaw which relate to definitions, coverage requirements, exemptions, and applications etc.
The purpose of the Toronto Green Roof Construction Standard is to govern the design and construction of green roofs by setting out minimum requirements that meet the City’s objectives and the Ontario Building Code requirements. Mandatory provisions are included in the Toronto Green Roof Construction for the following areas:
Toronto Building has prepared a guideline document to the green roof construction standard, in consultation with the City’s Green Roof Technical Advisory Group. The document contains “best practices” in green roof design, provides designers and the public with additional information on the Toronto Green Roof Construction Standard and contains illustrations to assist with calculating required green roof coverage.
To request a copy of the Supplementary guidelines email sustainablecity@toronto.ca
The Guidelines for Biodiverse Green Roofs identify, describe and illustrate best practices for creating habitat and promoting biodiversity on green roofs in Toronto. They are intended to support and expand the Toronto Green Roof Construction Standard Supplementary Guidelines. These guidelines are primarily designed for use by architects and landscape architects involved in designing green roofs but they may also be of interest to others who wish to understand how green roofs can be designed to enhance and support biodiversity.
Design Guidelines for Biodiverse Green Roofs identify, describe and illustrate best practices for creating habitat and promoting biodiversity on green roofs in Toronto.
For a copy of the Guidelines for Biodiverse Green Roofs contact: sustainablecity@toronto.ca
For all development where a Green Roof is required under the Bylaw, the applicant may apply for an Exemption where the requirement is not met. An Exemption allows a smaller amount of Green Roof than is required under the Bylaw, provided that a cash-in-lieu payment of $200/m² is made for the reduced green roof area, and the application is approved by the Chief Planner. All funds collected as cash-in-lieu will be directed to the City of Toronto Eco-Roof Incentive Program.
3. Payment of the cash-in-lieu is required to be paid by the applicant directly to Toronto Building (Customer Service) prior to issuance of the Building Permit.
This template is required to be submitted for all Site Plan Control or Building Permit applications where a green roof is required under the City of Toronto Green Roof Bylaw. Complete the table and copy it directly onto the Roof Plan submitted as part of any Site Plan Control Application requiring a green roof in accordance with the Bylaw.
Green Roof Bylaw Statistics Template
Buildings permit applications where a green roof is required or where a green roof is proposed to be constructed voluntarily must complete the the Green Roof Declaration Form.
For new development requiring Site Plan Control application, green roof statistics should be provided with the application to facilitate compliance with the Green Roof Bylaw at the time of Building Permit Application. Complete the template for the Green Roof Statistics and copy it onto the Roof Plan submitted as part of any Site Plan Control application or Building Permit application.
For Building Permit Applications associated with a Site Plan Control Application complete the Green Roof Declaration Form.
For new development requiring a Building Permit only complete the required Green Roof Declaration Form for submission at the time of Building Permit Application.
The Toronto Green Roof Construction Standard applies to all new building permit applications where a green roof is proposed. There are no additional fees for a building permit to construct a green roof that is part of an application for a new building or an addition to an existing building. A separate fee is charged for a permit to construct a stand-alone green roof.
As part of the Building Permit process for a Green Roof, Toronto Building staff must review your plans to ensure that they comply with the Toronto Green Roof Construction Standard, Ontario Building Code, local Zoning Bylaws and other applicable laws.
Staff Report: By-law to Require and Govern
the Construction of Green Roofs in Toronto (March 27, 2009)
Staff Report: Amendments to the Green Roof Bylaw for Industrial Buildings (October 19, 2011)