Toronto must wean itself off air conditioning even as heat waves get more severe, report says

A new report from Toronto Public Health is calling for new building code standards that would keep people cool and safe while reducing the city's reliance on inefficient air conditioning.

A survey found more than half of residents in older apartments have suffered heat-related illnesses

The report suggests 'passive cooling' measures can be as effective as air conditioning. (Jen Keiller/CBC)

Toronto Public Health is recommending changes to the provincial building code that would keep people cool while reducing the city's reliance on air conditioning.

The proposed changes include improving the quality of materials used on the exterior of apartment and condo buildings, as well as a new emphasis on "passive cooling" strategies to reduce the need for air conditioners.

The city's Board of Health will review the report —  titled "Reducing Vulnerability to Extreme Heat in the Community and at Home" —  at its Wednesday meeting.

"There's a variety of things that can be done on building envelopes, including upgrading to new windows, new walls, creating new insulation," said Ekaterina Tzekova, the building research manager for The Atmospheric Fund (TAF), which contributed to the report.

Tzekova says installing new overhangs and planting trees for shade can also make a considerable difference during summer months when the city can expect an increasing number of heat waves as climate change worsens.

Her research also suggests buildings with a centralized fresh air supply should consider cooling that air, rather than installing air conditioners in each unit.

"A lot of the time those [strategies] can have just as great of an impact as an air conditioner," Tzekova said, adding that Ontario's Ministry of Municipal Affairs would be wise to study a variety of strategies and include the most effective solutions in future versions of the building code.

Protecting buildings 'as urgent as climate change'

In a survey, Toronto Public Health has found that more than half of residents in "older apartment buildings" experience symptoms of heat-related illness.

The Board of Health chair, Coun. Joe Mihevc, says there could be dire consequences if the city and province do not implement solutions, since climate change research suggests heat waves could become more severe in the coming years.

"We don't want to get into the situation that happens in small numbers right now in Toronto but big numbers in other jurisdictions when they have heat waves, where people are literally dying in their apartments," Mihevc​ said.

The report also calls for the owners of buildings without air conditioning to provide indoor cool rooms for tenants during heat waves. Mihevc suggests some buildings could actually have two such indoor rooms on opposite sides of the structure to make sure at least one is out of direct sunlight at all times during the day.

"These are issues that building code officials will have to review and put into the building code as it is renewed and renovated every few years," he said.

Researchers say some new Toronto buildings are poorly equipped to handle heat waves. (Canadian Press)

Cooling Toronto's glass ovens

Along with retrofitting older buildings, changes to the building code might also improve conditions in some of the city's poorly-designed new developments, according to the TAF.

"We haven't necessarily got those types of building forms right," said Tzekova of the glass-clad towers that dot the downtown skyline. "In a lot of those buildings we're relying on mechanical [solutions] to make up for a weak envelope."

Mihevc is also concerned that some of those new buildings are difficult to keep cool and are therefore, energy-inefficient.

He's heard anecdotally that some units with floor-to-ceiling windows become "ovens" in the summer, "something that has to be looked at more carefully," Mihevc said.


Nick Boisvert is a multimedia journalist at the CBC's Parliamentary Bureau in Ottawa. He previously covered municipal politics for CBC News in Toronto. You can reach him at