A new building in downtown Toronto is tearing down the roof and adding new floors

The architects and builders renovating the Cambridge Suites hotel on the edge of Toronto’s financial district say their plans will take construction techniques in the city to a whole new level. It seems that they are not exaggerating.

The development proposal for the 21-story property on Richmond Street East, near the city’s towering bank towers, will begin by removing the peak roof of the 1990 postmodern building.

It will be replaced by an additional 50 storeys, bringing the new project to 757 feet (230.85 m) tall, on par with neighbors such as the Toronto-Dominion Center (731 feet).

It is a complex project that requires the construction of a 10-meter-high bridge structure on top of the existing hotel, with the roof removed. The bridge will help support the weight of the new tower, explains Len Abelman, principal of Toronto’s WZMH Architects, the firm designing the renovation for the property’s owner, Centennial Hotels Ltd.

“It’s not a common technique, it’s challenging. Together with a company called RJC Engineers, we did simulations regarding the weight and load of the weight and the lateral forces the building would face to ensure its functionality,” says Abelman.

“Other projects in Toronto have added floors in the past, but it’s usually done with a large exoskeleton that spans the entire building. This uses a technique that transfers some of the weight to the columns and floors of the structure below,” he says.

The site’s hotel, which currently offers 231 suites for business travelers, will be converted into 565 residential buildings with ground-level retail and commercial businesses; 42 percent of the apartments will be two- or three-bedroom apartments to meet the city’s requirements for more family-sized downtown apartments.

In September, the developers commissioned Bousfields Inc. to prepare a design justification document as they seek zoning and official plan changes from the City of Toronto.

Bousfields explains that the current hotel is located in an area of ​​downtown Toronto designated by the city as a “strategic growth area … to allow for intensification and higher density mixed-use in a more compactly built form.”

Return to the office

The long-term idea is to develop city center properties, such as Cambridge Suites, to reflect the changing patterns of people’s lifestyles and work habits. As the pandemic recedes, people are slowly drifting back to the office, but it’s not quite a storm.

In mid-August, the percentage of people going to offices in Toronto was still 30 percent of pre-pandemic levels, according to the Strategic Regional Research Alliance (SRRA), an independent research group that tracks changing work patterns.

“Adding housing to the economic core is a real act of urban construction. It will affect the people who live and work there,” says Alan Vihant, CEO of Elan DEV Group and spokesman for the developer consortium.

“And we believe that can be done by realigning and expanding the existing building.”

The city’s own growth plan calls for more urban areas where people could live close to the workplace and move around without a car. The Cambridge Suites hotel is located half a mile from six Toronto Transit subway stations, including Yonge/Queen and Union Station, which will eventually become transit hubs for the new lines.

“People are starting to go back to offices at least three or four days a week. But they don’t want long commutes to get there,” says Vihant.

Like almost all new construction today, the new project also aims for better environmental and sustainability standards than older buildings. According to Natural Resources Canada, 13 percent of Canada’s greenhouse gas emissions come from the construction industry, which is the third largest source of emissions.

Environmental benefits

The new tower is more thermally efficient than the current building, with bird-friendly glass and 41 square meters of green roof, says Michael McClelland, founding principal of ERA Architects, also on the project. There are only 21 car spaces in the project, while there are more than 570 bicycle parking spaces.

However, Mr. McClelland cautions that the building is not officially a fully state-of-the-art green building, as its design incorporates the existing hotel structure.

However, this construction technique brings other environmental benefits; Using an existing building as a load-bearing base instead of demolishing it helps fight climate change by keeping carbon in the building material.

This reduces the emissions that would be caused by demolishing the existing structure and replacing it with a new building.

“The city’s current guidelines don’t yet have anything about buried carbon retention, but Toronto and other cities have embraced this idea when developing new sustainability codes,” says McClelland.

His firm was also asked to look at potential heritage aspects that might arise from the redevelopment of the area, he adds. But the building is only 42 years old, so it’s not particularly iconic or symbolic, he says.

It will probably take about 18 months to complete the zoning process with the city, and up to six years to complete the project, says Vihant. But WZMH’s Mr. Abelman says the renovation is already looking into the future.

“This weight bearing technology we use is 2020s technology – I’m not sure it would have been possible just a few years ago,” he says.