By Tracy Hanes
The higher you go, the more challenging it can become
Keeping up with the number of new homes needed in Ontario has been a tall order. The solution in many urban centres has been higher density—and in Toronto and other larger cities, that’s resulting in taller residential buildings. Some are climbing to heights never before seen in the province, or the county. But building skyscrapers comes with lofty challenges.
Richard Witt, principal at BDP Quadrangle and chair of the Canadian chapter of the Council on Tall Buildings and Urban Habitats, says 40-storey buildings used to be considered tall, and they’ve been built in abundance in the GTA for decades. But since high-rise living caught on in the Toronto core a decade and a half ago, buildings have inched upward.
Witt says 40 storeys on a 1,100 square metre floor plate are the magic numbers. The City of Toronto has used this format to develop guidelines, with other Ontario municipalities following suit. Once you get above 50 storeys, though, things get structurally trickier, with wind and gravity loads requiring reinforcement.
Even so, some developers are choosing to build beyond those heights. Among them are Rogers Real Estate Development Ltd. and Urban Capital, developers of M City in the Mississauga city centre. Many of the eight towers in the master-planned community are tall (the completed M1 and M2 are both 62 storeys) with M3, under construction, to be the tallest, at 81 storeys plus a crown. When complete, M3 will be Canada’s tallest tower west of the GTA.
“We wanted this to be a showcase site for iconic architecture,” explains Adam Segal, director of construction at Urban Capital. “We are trying to bookend the Mississauga downtown. We wanted to come up with tall towers to complement the ‘Marilyn Monroe’ (Absolute World) towers, and the city was on board.”
Stranding 50 and 56 storeys, the curvy ‘Marilyn Monroe’ towers, built by Fernbrook Homes and Cityzen Development Group, were awarded Best Tall Building in the Americas in 2012 by the Council on Tall Buildings and Urban Habitat. Their unique design put Mississauga on the map internationally.
With M City, the plan was to have buildings of staggering heights around the tallest, M3. With several super-tall buildings in the design, the overall plan, including the required density
and satisfying the city urban design staff was a big undertaking. That requires developing a good relationship with the city staff, says Segal.
Although part of Mississauga is in Pearson International Airport’s flight path, which limits height, this wasn’t a consideration for M City, says Segal. But there were other issues. Getting workers and materials up and down high-rises during construction is always a challenge, but in the case of M City towers, the biggest challenge has been wind.
Segal says residents of high floors may get motion sickness if a building isn’t stabilized properly. To help suppress motion, M1 and M2 each have two splash tanks on the 62nd floors—roughly one-storey tall and one-third of the floor plate.
However, for M3—a taller, slenderer tower on a smaller footprint—a splash tank wasn’t going to suffice, so an international wind consultant was hired. Their solution was a tuned mass damper—essentially a massive 700-ton steel weight. It will act as a suspended pendulum between the 76th and 78th floors, swinging slightly to counter any tower movement. A similar solution was used at the 101-storey Taipei 101, the world’s 11th-tallest tower
To get workers and materials high into the sky, hoists with landings on the outside of the tower are typically used, says Segal, and these can take up a lot of frontage, as they are stacked along a building’s width. The hoists/landings are used to get workers in and out of the building, and to deliver materials. Typically, a bank of four conventional hoists would encumber finishing several suites.
At M3, a different hoist system was used, referred to as a common tower, where the same number of hoists (four) can be achieved, but only encumber the finishing of one suite on the typical floor.
An ACS – Automatic Climbing System – is being used to form the core of the tower around the elevator and stairs. The inside formwork is fixed and raised by hydraulic cylinders. Outrigger beams suspend the outside formwork, that can be moved horizontally to allow rebar to be placed. Once the rebar is placed, the outside formwork can be set in place (sliding along the outrigger beams) to cast the wall. Once complete, the entire system rises to the next floor above. This eliminates using a crane for the majority of this work, says Segal.
The conventional method would be to release forms, bring them back to the ground, do rebar for the next floor, then bring the forms back up, creating a lot of crane time and more impact from weather. A concrete pump is also being used at M3 to eliminate the need to haul buckets of the material up the building.
A third system employed at M3 is a Railing Climbing System (RCS) that provides a protective wind screen around the perimeter of the building, and shields against the elements. Conventionally, a fly form, or table form, is used to make the slabs (or floors). It’s a mold of sorts, made of plywood. Layers of steel are set up top of the wood with electrical and mechanical lines, then concrete poured on top. Once the concrete sets, the form or ‘table’ is pulled out beyond the face of the building by a crane, then moved up to the next level.
The RCS prevents the table from being slid beyond it on the building’s exterior, so the developers went with a table system that breaks down by hand and can be carried to the floor above by the staircase. Wind is not a factor, as this is done in a controlled environment.
Witt’s firm has designed the CG Tower, with construction almost complete, in the Vaughan Metropolitan Centre (VMC). At 60 storeys, it is significantly taller than any other building in the city. Though there are a number of new towers in the area, Vaughan lacks a landmark building. The CG Tower will fill that gap. Overlooking the largest city-owned park in the VMC, it is the fifth and final tower in Cortel Group’s master-planned Expo City.
Witt says Vaughan’s earlier character was based on low-rise living, and while the VMC marks a shift to a high-rise character, some of the previous towers’ designs were tentative about reflecting that change. The CG’s design and scale are bold. To give it a “homes in the sky” flavour, the tower is brick rather than glazed, but much planning was required to use that material at such a large scale. The CG Tower has stepped silhouettes to reduce its mass, while still creating a distinctive profile on the skyline.
“You want a landmark, but you don’t want every building to scream out for attention,” explains Witt, who says the supporting cast, while well-designed and attractive, can consist of more modestly designed edifices such as the stores, offices and apartments.
Witt says people have long complained about the homogeneity of Toronto buildings—both in terms of design and materials—but “you can see architecture in the city now” with more interesting buildings getting constructed.
The commodification of housing has been driven by economics, Witt explains, with considerations such as how people will live there, the absorption rate of units, and the cost of borrowing money. All are deterrents to building taller than 50 storeys.
Scott McLellan, chief operating officer of PlazaCorp, says his company prefers to remain beneath that threshold, even in the City of Toronto. Recent projects include the 32-storey 5858 Yonge St., 47 storeys at 400 King St. West and 48 storeys in the Theatre District. An exception is Plaza’s 1 Yorkville tower at 56 storeys.
“We don’t often want projects higher than 48 to 50 storeys, as the cost impacts success,” McLellan explains. “It’s harder to bring kitchens and workers up, and it takes a lot longer. Under 50 works, but after that, you have diminishing returns. At a certain (height) you have to put equipment in a building so that it doesn’t sway as much, and that’s a costly thing to do. It has an impact on the architectural design of suites and the exterior. It’s not impossible, but it is problematic and adds expense.”
McLellan says the cost of building higher must be offset by suite costs. For instance, if the cost increment is $1,000 per floor, a suite 60 storeys and beyond would cost $60,000 more than a first-floor version.
Plaza typically strives for parking spaces based on 40%-50% of the number of units in a building, with two levels of underground parking. Given a common footprint, a taller building means more units, which means more required parking spaces. Then there’s the matter of access. Plaza plans on one elevator per 100 suites, so about five elevators in a 50-storey building. Anything over 55 storeys requires additional elevators.
“You have to think about your market too,” says McLellan. “A smaller boutique building will have bigger suites, more end users and fewer investors. The suites are priced much higher. If you’re building towers, whether they are 30 or 50 storeys, it’s the same philosophy. You need smaller suites to meet the price point, and you need to sell 75%-80% to start construction. A 55-storey building may require another three or four months of carrying a construction loan before closing than a slightly shorter one.”
McLellan may have a point. The One, an unfinished mixed-use condo tower at 1 Bloor St. by Mizrahi Developments that was to rise 76 storeys, went into court-ordered receivership in 2023. It then went up for sale in mid-2024, with creditors seeking a minimum bid of $1.2 billion. Due to defaulted loan payments, the tower was $1.5 billion in debt.
Cost of Being Green
Toronto’s coming Green Standard Version 4 is also going to make it “incredibly expensive” to build taller, McLellan says, estimating it will easily add $60,000 to $70,000 to the cost of a suite. He believes this will significantly slow the 416 condo market, with less construction and less affordability. To meet those standards, he predicts we’ll see far fewer glass buildings and more masonry ones, and that balconies on towers will disappear.
But that’s not necessarily a bad thing. Balconies, Witt says, are a “weird Toronto conundrum.” From his office window, he sees a condo building that has balconies, but he never sees people on them—people love the views they offer but rarely use their balcony on windy days, he says. “There’s the idea that you need a balcony for resale, but it’s a funny attitude. When you look at luxury developments, they don’t have balconies. But you need a big terrace.”
While balconies are small, elevated platforms attached to the exterior of a tower, terraces are larger outdoor spaces, usually found on the ground floor or rooftops, and can be private or a common amenity. They can also be found at other levels if a building has a stepped design, or on top of a podium.
Balconies are a loss leader as they are costly to construct on tall buildings, indicates McLellan, calling them a “bad detail” that creates thermal bridging and energy inefficiency and that allows for water and moisture penetration. As the expression of tall buildings is being rethought, he says, in terms of materiality and form, balconies will become less commonplace, especially in rental buildings where landlords are seeking energy efficiency and to minimize potential future maintenance. And with the 416 condo market slowing and fewer investor buyers, McLellan expects developers to build more rental projects.
Despite the challenges in building them, Witt still predicts the rise of super-tall towers in other GTA cities, centred around transit. CentreCourt Developments plans to build 10 high-rise condominium buildings around the Pickering Town Centre, as tall as 55 storeys. The City of Hamilton will get its tallest building with Tercot Communities’ 45-storey condo at the Pier 8 waterfront development. In Ottawa, Trinity Centre near LeBreton Flats was approved in 2018 for 65 storeys, although construction has yet to commence.