Ontario repeals Toronto’s green roof requirement, threatening stormwater and climate plans
Provincial repeal of Toronto’s Green Roof By-law removes a 15-year mandate that created 1,200+ green rooftops and a $50-million local industry, raising infrastructure and flood risks.
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By Torontoer Staff
The Ontario government has repealed Toronto’s Green Roof By-law and introduced wider changes under Bill 60, removing the municipal requirement that new large developments include vegetated rooftops. City officials and developers say the move was made without meaningful consultation and could undermine stormwater management, climate targets and a local green industry.
The by-law, in place since 2008, supported more than 1,200 green rooftops in Toronto and helped build a roughly $50-million local sector. City leaders warn that scrapping the mandate will shift costs and climate risks onto residents and property owners.
What the repeal changes
The Green Roof By-law required new developments above a certain size to install vegetated roofs. Those roofs capture and slowly release stormwater, reduce urban heat, and improve building energy efficiency. With the provincial repeal, those installations become optional. The City of Toronto says the change weakens a tool it has used for 15 years to manage climate impacts.
How green roofs function in the city
Green roofs store rainfall, easing pressure on storm sewers during heavy events. They also lower rooftop and neighbourhood temperatures, helping to reduce heat-related health risks. Toronto’s programs have diverted hundreds of millions of litres of stormwater and contributed to emissions reductions through better building performance.
- Over 1,200 green rooftops installed since 2008
- About $50 million in annual local industry activity tied to green roof work
- Measurable diversion of hundreds of millions of litres of stormwater each year
- A role in reducing urban heat and improving energy efficiency
City officials and developers respond
Deputy Mayor Gord Perks and Mayor Olivia Chow’s office say the province did not consult Toronto before repealing the by-law. Both described the decision as a surprise and warned of practical consequences for infrastructure and residents.
We were utterly surprised by the province doing this. There’s a portion of the City of Toronto Act that says that the province should consult in good faith with us before making changes, and they just didn’t follow that agreement. They just blindsided us completely.
Deputy Mayor Gord Perks
Perks said removing the by-law increases the risk of sewer overloads, catastrophic flooding and billions in downstream infrastructure costs. He added that basement flooding, already a frequent and costly problem for homeowners, could worsen if stormwater is not managed on site.
Developers say they were not consulted either. Joanna Jackson, Vice President, Sustainability and Innovation at Minto, said the company has included green roofs on its Toronto projects for years and that the change was unexpected.
That was very much a surprise. I was not expecting that move by the province. We haven’t heard anything from the city yet.
Joanna Jackson, Minto
Jackson called for a balanced approach that keeps wider community benefits while addressing housing affordability, suggesting cost-sharing models between developers, municipalities and the province.
Economic and infrastructure stakes
Industry leaders warn the repeal could shrink demand for green roof services and cost local jobs. City staff say green roofs are a low-cost adaptation compared with major sewer upgrades that would be needed if stormwater is not detained at building sites.
Toronto’s broader climate agenda relies on municipal tools such as green roofs, energy retrofits and zero-emission transit. The city highlights ongoing initiatives, including transitioning the TTC fleet to zero-emission buses, retrofitting 80 per cent of city buildings and a $300-million Toronto Hydro investment to electrify the grid.
What comes next
City officials are reviewing Bill 60 and exploring responses. Deputy Mayor Perks said the legislation contains other concerns, including impacts on pedestrian and cycling safety and tenant protections. Municipal leaders are framing a challenge on the grounds that the province failed to consult.
Meanwhile, developers and industry groups may pursue voluntary practices or advocate for alternative policies that preserve the community benefits of green roofs while addressing affordability pressures.
The near-term impact for Toronto residents
In the near term, homeowners and property owners face elevated flood risk and potential increases in insurance and municipal costs if stormwater management shifts toward expensive infrastructure projects. City leaders argue those costs will fall on taxpayers and on private property owners through more frequent basement flooding and emergency repairs.
Perks and other officials say the decision undercuts local control over climate adaptation and places a larger burden on residents as storms become more frequent and intense.
If we can’t manage wet weather, snow, and rain on site, the amount of water running into our storm system, our storm sewers will just overload their capacity, and we will have catastrophic events.
Deputy Mayor Gord Perks
For now, Toronto faces the choice of pursuing legal and political options, encouraging voluntary uptake from developers, or redesigning municipal strategies to compensate for the loss of a tool that combined climate mitigation, urban cooling and local economic activity.
The repeal removes a regulatory lever the city used for 15 years to shape development that supports climate resilience. City officials and industry groups must now weigh whether to press for reinstatement, seek compensating measures, or adapt to a new regulatory environment.
green-roofsclimate-policyBill-60Torontourban-planning
