It's a story that has been repeated ad nauseum in Toronto over the past decade. Developable land is scarce. Demand for housing is high. Land value is skyrocketing. And the only way to go is up. Density is the magic word on everyone's lips, whether it is uttered with excitement and adoration or with contempt and disgust. Regardless, denser developments represent the future of Toronto, and through it all, City Planning is grappling with the ultimate urban conundrum of the 21st Century: how much density is too much?

Among Toronto's forest of construction cranes, the Entertainment District stands out as the poster child of integrating high-density mixed-use development within the city. By UrbanToronto's count, within the roughly 0.6 k boundary of Queen Street, Spadina Avenue, Front Street, and University Avenue, there are approximately 35 towers proposed or under construction that measure 20 storeys or higher, in addition to the roughly 15 to 20 towers of that height already completed over the past decade. The new residential unit count numbers in the tens of thousands; the square footage of new commercial and office space stretches into the millions.

One node in particular within the Entertainment District stands out as being particularly challenging. On a single block bordered by Adelaide Street, Duncan Street, Pearl Street, and Simcoe Street - measuring roughly 2.8 acres (11,350 ) in area - four separate developments are seeking to add four different towers, the smallest of which rises 25 storeys, the tallest reaching 59 storeys. The totals for the block, if everything is built as proposed, are: 1,596 residential units; 192 hotel suites; 475,223 f (44,150 ) of office space; and 37,135 f (3,450 ) of retail/commercial space.

Map of development around the Pearl-Duncan intersection, image by Julian Mirabelli via Google Earth.

Of the four proposals on this block, 150 Pearl stands out as a long shot for approval, and is an example of just how far landowners might go to squeeze as much density out of their property as possible. The building infringes on some of the City's recommended zoning and design guidelines, and might just constitute an overdevelopment. Let's take a closer look.

Situated in the southwest quadrant of the block and at the northeast corner of Duncan and Pearl Streets, 150 Pearl is proposed to rise to a height of 58 storeys with 480 condo units and roughly 3,916  of commercial space on the lower three floors. The skinny tower measures a mere 14 m in width (15.8 m including balconies) and is shifted toward the south edge of the property along Pearl Street with a 3-metre stepback from the property line above the podium.

Rendering of 150 Pearl, image courtesy of the Conservatory Group.

Considered on its own, 150 Pearl seems like a relatively harmless proposal, adding appropriate density in a desirable and transit-oriented neighbourhood while preserving a portion of a heritage building and a heritage facade at its base. But a look at its immediate context tells a different story.

Directly to the north, situated in the northwest quadrant of the block at the southeast corner of Adelaide and Duncan Streets, 19 Duncan is currently under construction. Set to rise 59 storeys with 462 residential units and 9 storeys of office space at its base, the tower will begin its ascent into the sky in 2019. This, however, poses an issue for 150 Pearl. 19 Duncan's tower is set back from its south property line only 10 metres, while 150 Pearl's tower is set back only 10 metres from its north property line, meaning there is a 20-metre separation distance between the two. The City's minimum is a 25-metre separation, but given 150 Pearl's constricted site, this would be problematic.

Rendering of 19 Duncan, image courtesy of Westbank and Allied.

Directly across the street to the south of 150 Pearl is the highly-anticipated Mirvish+Gehry, the pair of 81- and 91-storey supertall towers straddling Duncan Street along King that will bring up to 1,716 condo units, 201 hotel suites, and roughly 8,000 f of institutional space for OCAD University. Mirvish+Gehry has already been approved, but the owners have filed another rezoning application to increase the height of the towers. 150 Pearl just ekes out a 25.8-metre separation distance from Mirvish+Gehry's 81-storey tower to the south, but this still does not prevent much of it from perpetually sitting in its shadow.

Rendering of Mirvish+Gehry, image courtesy of Great Gulf.

Directly across Duncan Street to the west of 150 Pearl is another 48-storey tower proposed at 14 Duncan, situated on the northwest corner of Duncan and Pearl Streets. This tower would add a further 369 residential units to the area with retail in its base. This proposal is not yet approved and is seeking rezoning, and while it fits within the zoning guidelines with respect to 150 Pearl, it joins a rather busy area in terms of density.

Rendering of 14 Duncan, image courtesy of Greenwin.

Immediately to the east of 150 Pearl, 217 Adelaide West is proposed to rise 25 storeys with office and hotel uses. The tower stretches the full width of the block between Adelaide and Pearl Streets, and is built right up to its east and west property lines on its lower half, with the upper portion of the tower stepping back to a maximum of 2.2 metres on either side. The site plan looks either like a claustrophobic's nightmare or a hyper-urbanist's dream, with three 58 and 59-storey towers butting up against the building on either side. 217 Adelaide West is not yet approved.

Rendering of 217 Adelaide West, image courtesy of Humbold Properties.

Site plan for 217 Adelaide West, image courtesy of Humbold Properties.

Immediately east of 217 Adelaide West is the final proposal on the block, located in the eastern quadrant at 100 Simcoe. This tower is proposed to rise 59 storeys with 524 residential units and office space in its podium. 100 Simcoe is not yet approved, but fits within the City's zoning guidelines, with more than a 12.5-metre setback from its west property line bordering against 217 Adelaide West.

Rendering of 100 Simcoe, image courtesy of Bentall Kennedy.

The City is concurrently reviewing all of these proposals and assessing them with an eye to the future. In addition to determining whether they all fit within the relevant zoning regulations and design guidelines, City Planners must also determine whether the existing infrastructure can handle this much density; whether enough community services such as schools, parks, and community centres exist to handle the new residents; whether all heritage buildings involved are being appropriately treated; whether the towers will have an impact on the local microclimate in terms of wind speed at ground level, access to sky views, and sunlight penetration; and whether the existing road and transit network can handle the influx of pedestrians, cars, and service vehicles.

With regards to 150 Pearl, the City may also consider quality of life and privacy issues within the residences themselves. If everything in the vicinity gets approved and built as is, 150 Pearl will be surrounded by towers as high or higher than itself, with sight lines perpendicular from its 4 facades as small as 20 metres and no more than 50 metres, all staring directly into adjacent buildings. It may also experience considerable shading from Mirvish+Gehry and the previously completed 47-storey Theatre Park Condos to the south.

Rendering of all proposed and existing developments in Entertainment District, image by Forum contributor Koops65.

City Planning and the LPAT are currently trying to untie this knot of density and determine what can and cannot be built while trying to maintain the highest quality of life for all affected parties. Regardless of how this tangle is resolved, it provides an interesting case study into the question of how much density is too much.

You can tell us what you think of the projects mentioned above and how you think this density issue should be resolved by leaving a comment in the space provided on this page. Check back for updates on each of these proposals, and in the meantime, you can join in the discussion in each of their associated Forum threads, linked below.

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Related Companies:  Allied Properties REIT, architectsAlliance, Ashlar Urban Realty, Bentall Kennedy, Brad J. Lamb Realty, Brandon Communications, Conservatory Group, Cushman & Wakefield, Diamond Schmitt Architects, Dream Unlimited, ERA Architects, GBCA Architects, Gehry Partners, Great Gulf, Greenwin, Harhay Developments, Hariri Pontarini Architects, Humbold Properties, II BY IV DESIGN, Jablonsky, Ast and Partners, Janet Rosenberg + Studio, Juhan Marten Landscape Architect, Kirkor Architects Planners, Lamb Development Corp, MMM Group Limited, Montana Steele, Niche Development, Page + Steele / IBI Group Architects, Projectcore, Quadrangle, Richmond Architects, RJC Engineers, Terraplan/Studio TLA, Westbank Corp, Westdale Properties, WSP