Green Roofs - Living Architecture Monitor - Fall 2010 - (Page 2)

STRATA T.O.’S NEW GREEN ROOF CONSTRUCTION STANDARD POLICY FIRST OF ITS KIND IN NORTH AMERICA By Dylan Aster O n January 31, 2010, the City of Toronto’s Green Roof Construction Standard came into force, marking the start of the first comprehensive standard in North America regulating the design and construction of green roofs. The timing coincides with the launch of the City of Toronto’s new Green Roof Bylaw. Both initiatives aim to further the evolution of the city’s green roof strategy. The standard is a key component of the Toronto Green Roof Bylaw. The bylaw requires that all new residential, commercial and institutional development above 2,000-squaremetres of gross floor area have a green roof. There is a graduated coverage requirement ranging from 20 to 60 percent of the roof area. The bylaw will apply to new industrial development starting January 31, 2011. The standard is an exception to provincial legislation that generally does not allow a municipality to regulate an aspect of building construction. The standard has been designed to dovetail with existing Ontario Building Code requirements and objectives, while also addressing the components of a green roof that make it “green.” The standard is clear in its design that it does not conflict with, or exceed any code provisions. The standard is authorized by the City of Toronto Act, 2006. An early draft of the construction standard was subjected to public consultation and a review by the Toronto Green Roof Technical Advisory Group (made up of nominated representatives from various industry associations including Green Roofs for Healthy Cities). The group was chaired by Ryerson professor Hitesh Doshi. The group’s recommendations were included in the revisions to the standard, which was ultimately adopted by Toronto City Council in May 2009. It is estimated that widespread implementation of green roofs in Toronto could save the City between $40 million and $120 million in stormwater infrastructure costs, as well as reduce the impacts of the urban heat island effect by lowering local ambient temperatures by up to two degrees Celsius. The new Green Roof Bylaw is expected to add 50 to 60 new green roofs in Toronto each year, helping to cool the city. Dylan Aster is program manager, Office of the Chief Building Official, City of Toronto. For more information, visit

Table of Contents for the Digital Edition of Green Roofs - Living Architecture Monitor - Fall 2010

Green Roofs - Living Architecture Monitor - Fall 2010
From the Founder - Urban Agriculture
Strata - T.O.’s New Green Roof Construction Standard
On the Roof With…Richard Conlin
Project - Farming for the City
Beekeeping - Diary of an Urban Apiarist
Exemplary Design - GRHC’s 2010 Awards of Excellence Winners
A Green Roof That Moves
Steeped in Ecological Design
Creating Community
A Model of Municipal Leadership
A Green Roof That Works
Like a Grassland Stream
Prairie in the City
Recycling Rainwater
Research - Increasing Urban Food Security With Extensive Green Roofs
Economic Valuation of a Rooftop Food Garden
Grhc Update - Macro-Scale Food Production
New Corporate Members
New GRPs
On Spec - Urban Agriculture — Hero or Hype?

Green Roofs - Living Architecture Monitor - Fall 2010