Toronto is certainly no stranger to height. Home to the iconic CN Tower, we proudly laid claim to the tallest freestanding structure in the world for 32 years from 1975 to 2007. Rising side-by-side with it was First Canadian Place, the city's second-tallest structure and still the tallest building in Canada, also completed in 1975. Since that initial thrust into the clouds, Toronto has populated its skyline with a myriad of towers, but none of which have breached the benchmark set by the city's two tallest structures.

View of the Downtown skyline from Ontario Place, image by UrbanToronto Flickr Pool contributor wyliepoon.

Recently, however, First Canadian Place's claim as the tallest building in Canada is under threat, as a new wave of towers are in the works that look to surpass its 298-metre height. Currently there are six candidates vying for the title of Toronto's tallest building (as opposed to a tower, of course), each at various stages of the planning process. These proposals aim to join the global trend of the 'supertall', defined as any building that surpasses 300 metres in total height (1000 feet in imperial units)—a title that First Canadian Place sadly missed out on by a mere two metres.

Let's take a look at the six supertall candidates in the city, and delve into a quick analysis of this recent phenomenon, looking at how Toronto might be dealing with the impending increase in height.

Map showing the location of the six supertall towers, image via Google Earth.

YSL Residences: 343.9 metres

By far the tallest of the proposed towers, Cresford Developments' 98-storey mixed-use behemoth is slated for the southeast corner of Yonge and Gerrard Streets. Kitty corner to the soaring Aura tower, which currently holds the title of Canada's tallest residential building, YSL Residences is designed by Kohn Pederson Fox alongside architectsAlliance, and is looking to join the quickly densifying Yonge Street Corridor north of the Financial District. Replacing a row of low-rise storefronts, the tower as proposed would land 10,000m2 of retail, 11,000m2 of office space, and 957 condominium units onto the site, while retaining a pair of heritage facades at its base. Notably, more than 50% of the condo units are proposed as two bedrooms or more.

Rendering of YSL Residences, image courtesy of Cresford Developments.

At the moment, YSL is seeking both rezoning and Official Plan Amendment approvals from the City, so this project is by no means a sure thing. Cresford is hoping to have its plan considered a resubmission of a previous proposal by KingSett Capital, a development of two towers of 62 and 73 storeys on the site, which would likely save time and money on the process. However, this is still only the first iteration of Cresford's design, so expect some tweaks to happen as the City reviews the application. Registration has opened, but there is no timeline given for when this building may materialize.

Rendering of YSL Residences, image courtesy of Cresford Developments.

One Yonge Street, Tower One: 307 metres

Coming in second place height-wise is Pinnacle International's 95-storey mixed-use tower, located at the foot of Yonge Street near Toronto's waterfront. Known officially, for the time being, as Tower One—even though it will not be the first tower to be built here—the supertall structure is part of a larger master plan at 1-7 Yonge to redevelop the Toronto Star Lands into a new mixed-use community. The Hariri Pontarini Architects-designed master plan includes five towers measuring in at 95, 80, 65, 35, and 22 storeys, with the three tallest slated for residential use clustered on the north half of the site, and the two shortest slated for office use located on the south block, separated by an eastward extension of Harbour Street. The first tower to sink shovels in the ground will be the 65-storey Tower Three, as it contains a new community centre for the waterfront district; the 95-storey Tower One is next in line for Phase 2.

Rendering of 1-7 Yonge, image courtesy of Pinnacle International.

Tower One is proposed to contain 1,123 residential units, the majority of which will be one bedroom, while 228 affordable housing units (roughly 10% of the total unit count of the master plan) will be included in the shared podium of the three residential towers. Tower One will also include a 114-suite hotel and roughly 1,600 square metres of retail space in its podium. It will be complemented by a new POPS at the northwest corner of the site.

Rendering of 1-7 Yonge, image courtesy of Pinnacle International.

Anson Kwok, Vice President of Sales and Marketing at Pinnacle, explained that the entire scheme has been five years in the making, and having worked closely with the City and stakeholders during that time, he is optimistic that the entire community will materialize as a successful addition to the waterfront district. The design came about from a desire to create a landmark development that occupies a prominent spot in the downtown skyline, a "modern-day lighthouse" that anchors the foot of Yonge Street, Toronto's important central spine. The variation in height and expression of the five towers creates architectural interest, avoiding a bland skyline of repetitive buildings. As a collection of some of the tallest structures in the city, the 1-7 Yonge will certainly have a lasting impact on the image of the city.

1-7 Yonge's rezoning has now been approved, so the 307-metre height limit of Tower One has received the City's blessing and has moved one step closer to reality. However, several major steps still need to happen before we see the tower materialize: it must go before both the City and Waterfront Design Review Panels as well as being submitted for Site Plan Approval, where it will be subject to review by City staff, followed by sales and marketing and finally, if all goes according to plan, mobilization for construction. This means that the design of Tower One may still change and should not be considered final. There is no timeline for when construction may start on this tower, however, it is currently well on its way to rising into the sky.

Rendering of 1-7 Yonge in context, image courtesy of Pinnacle International.

The One: 306.3 metres

Just two feet shy of One Yonge's height, but likely the first of the supertall towers we will see constructed, Mizrahi Developments' The One is slated for the southwest corner of Yonge and Bloor Streets. Designed by world-renowned starchitects Foster + Partners alongside Core Architects, the tower will rise 82 storeys above one of the busiest and most important intersections in the city. The building will contain six floors of retail at its base (plus one additional below-grade floor of retail that connects to the Yonge-Bloor PATH system), followed by 10 floors of hotel use, above which will be 416 residential suites.

Rendering of The One, image courtesy of Mizrahi Developments.

Sam Mizrahi, President and Founder of Mizrahi Developments, described the project with enthusiasm and optimism in a recent conversation with UrbanToronto. He touted an excellent working relationship with the City, advisory groups, and local working groups as contributing to the success of the design process. The One has gone through several iterations over the past two years, most notably a reduction in height due to concerns over shadow impact, and a reconfiguration of the tower's signature exoskeleton structure. Mizrahi adds that the exoskeleton, a first for Toronto, goes beyond giving a distinct aesthetic to the building by allowing for floor plates devoid of any columns, which presents a certain degree of freedom for residents and tenants to customize their units.

The One was recently approved for Site Plan Control at the OMB. Demolition on the site is nearly complete, and construction is scheduled to begin in September, followed by the launch of the sales centre at the end of that month. With nearly 4000 people pre-registered to purchase one of the 416 units available, it is unlikely that Mizrahi will have issues selling the highly-coveted suites. The One has created quite the buzz in Toronto, and it won't be long before we discover if it lives up to the hype.

Top of The One, looking south, image courtesy of Mizrahi Developments.

It should be noted that the quoted height of 306.3 metres refers to the top of the piers, and does not include the height of the parapet around the roof, the design of which has not yet been finalized. The final parapet may further add to the height of the tower, but it is unknown whether it will amount to the additional inches needed to bump The One up to second place in the height category. For the remainder of the building, Mizrahi confirmed that the design of the tower is now final and is not expected to change; what we see in the renderings is what we will get.

Of the six supertall towers, it appears that The One is winning the race to be the first one built, and may lay claim to the title of Toronto's—and Canada's—tallest building, however briefly, within the next few years.

Rendering of The One, image courtesy of Mizrahi Developments.

Mirvish + Gehry, West Tower: 304.3 metres

When it was first proposed back in 2012, the prospect of David Mirvish and starchitect Frank Gehry teaming up created quite the stir, notwithstanding the fact that the towers were among the tallest in the city. Projectcore, the developers heading the project, went through several iterations of Mirvish+Gehry before being approved for rezoning in 2014. Since then, however, news has been scarce, much to the chagrin of its fans, but an application for Site Plan Control was submitted in spring 2016, signalling that the project is still in the works.

The development consists of two towers flanking the intersection of King Street West and Duncan Street, situated along a busy stretch of King across from David Pecaut Square. The two buildings sport Gehry's signature deconstructivist style, articulated in a series of fragmented, staggered volumes finished with eclectic, undulating surfaces. The West Tower rises 92 storeys and breaches the 300-metre mark, while the East Tower totals 82 storeys and falls short of the supertall designation. The West Tower will contain 1,194 residential units, the majority of which will be one or two bedrooms, sitting atop a 7-storey podium. The podium will contain three levels of retail at its base, above which will be office space on the remaining four floors.

Photographs of the model of Mirvish+Gehry, image courtesy of Projectcore.

Robin Ramcharan, Project Manager at Projectcore, confirmed that the development is on track and moving along well. "We continue to explore programming, interior elements, and we are looking at interesting mixed-use components with built-in flexibility to allow for changes in the market," Ramcharan stated. "The process does take time but we remain on track and have made significant progress with major issues." Projectcore is determined to maintain the original design intent of the distinctive towers, as allowing Frank Gehry to leave his mark on the Toronto skyline was a driving force behind the height and expression of the towers. "When we hired Frank Gehry, we didn't want to constrain one of the world’s best architects to standard restrictions," says Ramcharan. "We believe it was important to make a statement that good architecture should take the lead, and we worked to find a balance with planning metrics."

The first of the towers on this list to be proposed, Mirvish+Gehry has been slow-moving, but appears to be inching its way closer to reality. Despite the lag, it is still one of the more advanced supertall towers, and perhaps falls second in line to be built; if all goes well, the unique buildings may be joining the skyline within the next few years.

Rendering of the podium of Mirvish+Gehry, image courtesy of Projectcore.

LCBO Lands Block 4, Towers B & C: 304.1 metres each

Moving back down to Toronto's growing waterfront, the final two buildings on our list come in the form of twin supertall towers that are part of Menkes' redevelopment of the LCBO Lands. Located immediately next door to 1-7 Yonge, the master plan for the LCBO site is proposed to host 6 towers measuring in at 89, 89, 80, 79, 75, and 25 storeys. Designed by architectsAlliance, the entire master plan aims to bring a total of 5,192 residential units, over 42,200 square metres of office space, and roughly 28,700 square metres of retail to the waterfront site.

North elevation of Block 4, image courtesy of Menkes Developments.

The site is divided into four blocks, bisected east-west by an eastward extension of Harbour Street, and divided north-south by Cooper Street. Block 1 in the southeast quadrant will contain a 25-storey office tower with the LCBO as its main tenant. Block 2 in the northeast quadrant would see two mixed-use residential towers of 79 and 80 storeys constructed, while Block 3 in the southwest quadrant is reserved for a new public park that will serve the influx of new residents to the East Bayfront. Finally, Block 4 in the northwest quadrant is slated to house the two 89-storey supertall towers along with the final 75-storey tower, each of them proposed to be mixed-use residential buildings.

Rendering of the LCBO Lands, image courtesy of Menkes Developments.

Phase One of the master plan is the 25-storey office tower on Block 1, while Block 2 is scheduled for Phase Two, where the 79- and 80-storey towers will be constructed. It is projected that Block 4 and the supertall towers will be the last phase of the development, where the twin buildings will be constructed atop the retained facade of the heritage LCBO office building.

Currently, none of these buildings have been approved; the master plan is still seeking rezoning, and Site Plan Applications have been submitted for the Block 1 and Block 2 buildings. It is still very early in the process, and given the phasing of construction, the supertall towers are a long way off from reality. It is very much a possibility that the design of this development may change, and the heights of the towers are not a guarantee.

Rendering of the base of the supertall towers in the LCBO Lands, image courtesy of Menkes Developments.

Supertall Toronto: Dissecting the Height Boom

It is fairly obvious that the recent building boom in Toronto has resulted in an increase in density and tall buildings across the city. But in modern-day cities, density can take many different forms. So why, then, are we seeing this density manifest itself in increasingly tall towers, pushing continually higher into the supertall category?

Each developer we spoke to regarding their respective supertall proposals cited a lack of available land, a strong desire for residents to live close to where they work and play, and the increasing demands of a short supply of housing as reasons why the height was necessary. Most important to each of their cases was the benefits of locating residents close to where they work and close to vital infrastructure: a shorter commute, a decrease in traffic due to less reliability on cars, increased walkability, and the advantage of capitalizing on existing or new services. In general, it appears that the City, landowners, and even residents are demanding a more efficient use of urban land, fuelling an upward push into the sky in an effort to accommodate increasing populations within a relatively small area.

Rendering of the potential future Toronto skyline, image by Forum contributor innsertnamehere.

Gregg Lintern, Director of Community Planning for Toronto and East York, explains that behind this push for density, the existing policy framework laid out in the Official Plan and provincial growth policies is facilitating intensification in urban cores, thereby encouraging taller buildings in the various centres. Combined with strict limits on developable land and the resulting rising land values, height is becoming more necessary to meet the needs of all parties involved.

Lintern cautions, however, that these supertall towers are not the norm, but rather the exception. A decade ago, the typical tower height was 20-30 storeys, with buildings higher than 40 storeys a rare exception. Recently, however, the norm has crept up to the 40-60 storey range, with buildings upwards of 70 storeys becoming the new exception. This gradual increase comes with added complexity in the planning process, one that the City is taking in stride.

The City does not have a hard limit set on building height; rather, the allowable height is very much dependent on context. With increased height comes a greater impact on the surroundings, both physically and socially; as a result, the taller the tower, the more stringent the review it is subject to, and the higher the standards it is held to. The demands of a supertall can place great strain on a neighbourhood, and as a result, more community benefits may be asked for from the developer, and more space may need to be allocated for infrastructure and services.

Rendering of Chelsea Green, image courtesy of Great Eagle Holdings.

This explains the lengthy planning process of Mirvish+Gehry, the first supertall to be proposed, and also explains the inclusion of several non-residential components of the project. Mirvish+Gehry was adjusted to include space for OCAD University, and also to make room for the preservation of two theatres, several heritage properties, and the creation of a new art gallery, each of which gives something back to the local community.

In the case of the supertall towers in the waterfront district, each building could potentially house upwards of 2,000 people, so the question becomes less about shadow impacts and more about whether the infrastructure exists to support the new residents. This is why both 1-7 Yonge and the LCBO Lands are being shaped as complete communities: between the two master plans, they include a new community centre, a public park and POPS, a new elementary school, office and retail uses, and the promise of new transit in the form of the East Bayfront LRT. It also explains why in both cases, the community or non-residential uses are being constructed first in order to implement the necessary services to support the incoming residents at a later date. The height will be allowed only if the proper infrastructure is in place to sustain it.

In the case of The One, community benefits played less of a role in shaping its final form than the physical form of the building. Unlike the other supertalls, many of which contain more than 1,000 residential units, The One amounts to a mere 416 condos, and is situated at a central location that already contains the necessary infrastructure to support it. The changes that the building went through during the planning process were mainly an effort to reduce its physical impact: it was made shorter to avoid shadowing nearby parks, and its floor plates were reconfigured to allow for the preservation of a heritage building.

View of 1-7 Yonge from the LCBO Lands park, image courtesy of Menkes Developments.

Supertall towers also come with a new set of technical challenges that designers and developers must overcome to ensure their success. Structurally, there is the increased wind load on the upper floors, and the complex foundations needed to anchor the building. Internally, there is the tricky problem of the elevators: the taller the tower, the bigger the elevator shaft, and the less usable floor area per storey there is. Vertical travel time also becomes an issue. In the case of YSL Residences, the top floors of the tower only house two or three units each. There is also the floor plate size to consider: nearly all of the proposed supertall towers exceed the recommended 750-square-metre maximum set by the City, which is usually necessary in order to have a viable tower.

If there is one criticism that Lintern has about supertall towers, it is the concern that they might create an expectation for more height in their immediate surroundings. This is most apparent at the intersection of Yonge and Gerrard Streets, where the 78-storey Aura has set a precedent for height at the intersection: there are now five towers over 70 storeys proposed within a one block radius, an area that was never intended to accommodate such height. Lintern stresses that it is all about the context: a neighbourhood may be able to support one supertall tower, but more than that may overload its capacity for quality of life if the necessary infrastructure does not exist, and the presence of one tall building does not necessarily infer that more are viable.

Looking north on Yonge Street, image by Forum contributor ADRM.

When it comes to tall buildings, the greater the height, the greater the responsibility. The higher the building, the more strain it exerts on its surroundings, and the more care and scrutiny that needs to go into its design and programming. This may explain why many applications are taking longer than expected; it is important to get it right the first time, because an 80-storey mistake is rather difficult to correct.

One question, though, remains: is there such thing as too tall? Is there a limit on how much height and density can be sustained in one building before any context can no longer support it? This question unfortunately cannot be answered as of yet, but as Toronto pushes higher and higher into the sky, it will encounter new challenges and face new conflicts that it will need to resolve, or learn to avoid, as it builds for the future. As we push past this frontier of the supertall, we venture into unknown territory and put to the test our planning policies and design abilities in the hopes of creating a functioning, livable city; only time will tell if we succeed.