Property Lines is a column by Curbed senior reporter Patrick Sisson that spotlights real estate trends and hot housing markets across the country. Comments, tips, and suggestions on where Property Lines should head next are welcome at patrick@curbed.com .

In Toronto, which is swelling with new developments, condos, and arrivals, the Well, a massive mixed-use project, shows how the city continues to evolve.

At the moment, the Well is a 7-acre hole in the ground near a rail junction in King West, just outside Toronto’s old downtown. It’s not much to look at. But when it’s complete, this seven-building development will include 1,800 residential units, more than 400,000 square feet of retail and dining, an underground thermal cooling system, and 1 million square feet of office space, all located near a streetcar line at the city’s Union Station.

It’s a vision for a “21st-century neighborhood,” urban designer Ken Greenberg told Toronto’s CityNews earlier this month. Richard Sommer, dean of the University of Toronto’s John H. Daniels Faculty of Architecture, Landscape, and Design, calls the Well “the epicenter of the Toronto phenomenon.”

New development is nothing new for Toronto: Thanks to its rapid expansion over the last decade, the city’s real estate industry has reshaped neighborhoods across a sprawling metro area.

With more than 400 proposed high-rise projects in the pipeline, according to Rider Levett Bucknall—including The One, an 85-story Foster + Partners-designed skyscraper set to be the country’s tallest when complete—it’s fitting that Toronto is the North American city with the most construction cranes for two years running. Sidewalk Labs’ partnership for a ground-up smart-city neighborhood in the waterfront Quayside district is just one of a number of megaprojects in the works.

That growth has brought significant challenges, like building out the city’s transportation infrastructure and coping with skyrocketing housing costs. While a recent change to mortgage rules briefly cooled the city’s red-hot condo market earlier this spring (which also caused the rental market to spike), housing prices have risen 60 percent in the last five years, and 3 percent this year alone.

“Compare the skyline of Toronto today to what it was like 15 or 20 years ago, and it’s almost unrecognizable,” says Jeremy Kronick, associate director of research at the C.D. Howe Institute, a Canadian think tank.

Toronto, with its fast-growing innovation hub, shows few signs of slowing down, and has room to densify (it’s less dense than Chicago or Philadelphia). As local columnist Christopher Hume wrote yesterday, urbanism is progressing despite previous planning shortcomings and sprawl. “There’s a growing awareness that what makes Toronto successful is that it’s a work in progress, more process than place,” writes Hume.

That’s why many say the solution to urban expansion in Toronto is scaling down, and focusing on community- and transit-oriented growth.

The condo boom and community development

Toronto, and the greater Toronto area, has, like most cities, seen development concentrate in a few areas. When the city expanded to its current borders in 1998—a process called amalgamation united Toronto with nearby cities, somewhat akin to the five boroughs joining to form New York City—the differences between downtown Toronto and its outlying areas became pronounced.

Toronto’s recent development boom has primarily focused on the old, central downtown district near Lake Ontario, and in a few high-rise residential districts that cluster along transit corridors. Yet before this, in the postwar period, Toronto sprawled with a curious mix of planned, low-rise communities and modernist towers—Sommer says the tower neighborhoods were developed according to a model not unlike those in Moscow during the Soviet period. Today, many of these aging towers in the city’s outlying areas serve as homes for new arrivals, especially the less well-off of the roughly 100,000 immigrants that settle in Toronto each year.

Central downtown Toronto and its inner suburbs may have once offered the promise of owning a single family home at an affordable price, but no more. As both Toronto and the demand to live downtown have grown in recent decades, a condo-building spree took root.

According to the Canada Mortgage and Housing Corporation, condos represented 49 percent of housing starts in 2016, up from 32 percent in 2007. Despite the brief cooling period this spring, new units continue to come online. According to a November 2017 report by the Ryerson City Building Institute, “Bedrooms in the Sky,” 105,000 units were under development, the highest number on record, with 94 percent pre-sold. That adds significantly to the 321,500 units already on the market, and underscores how much the market has shifted toward condos.

Rising prices, and a construction industry focused on condo construction, has left Toronto with a problem: a lack of much-needed affordable rental property—and too little development in the middle sections of the metro area. The greater Toronto area needs to add 8,000 new rental units a year through 2041 just to keep up with population demand, according to Graham Haines, research and policy manager for the Ryerson City Building Institute.

“Current prices in central Toronto mean a family-sized condo runs around $1 million,” Haines says. “That’s not exactly family-friendly for many.”

This coming wave of development hopes to address some, if not all, of these challenges.

”For access to land and affordability, developers need to look beyond the low-hanging fruit in old center,” says Sommer.

“Intensification” and increased competition for vertical living

Haines believes that, as condo development reaches a crescendo, developers are taking a closer look at smaller sites, and pitching more transit- and community-oriented development.

The forthcoming Waterworks condo development, an adaptive reuse of a 1930s utility building, will include a transitional-housing agency, affordable housing, and a sensitive adaptive reuse of a ’30s heritage building. A project called Mirvish Village, a redevelopment of an old electronics store known as Honest Ed’s, will contain a series of sub-30-story towers primarily made up of rental units. It’s part of a larger series of residential developments along the Bloor Street transit corridor.

A crosstown light-rail line on Eglinton Avenue, Eglinton Connects, has spurred more talk of transit-oriented development, and the stations on the new Spadina Line provide a node for development in the northern suburbs. In nearby suburban Mississauga, the 10-tower, $1.5 billion M City development is tied to the expected 2021 opening of a light rail line.

The city has also pushed for more affordable housing, part of an ambitious national plan to invest in affordable housing construction, as well as family-friendly development. Last May, the Toronto City Council approved “Growing Up: Planning for Children in New Vertical Communities,” a set of guidelines for developing more family- and kid-friendly condos that includes guidelines for public space and parks. As Jennifer Keesmaat, Toronto’s former chief planner, told the Star, many previous high-rise towers were criticized for not being walkable or having a strong sense of community, but that seems to be changing.

The high-rise and condo boom isn’t slowing down; developer Great Gulf is working on a pair of towers for the Mirvish-Gehry project west of downtown that seem to reference the architect’s work on the New York by Gehry.

But, as Bedrooms in the Sky underlines, demographic projections suggest the city needs to act fast to address affordability issues and the challenge of densification (sometimes called “intensification”). Between 2016 and 2026, the city’s 35-to-44 age group—prime time for millennials buying a first home—will grow by 207,000, just as the number of downsizing seniors booms by 484,000 residents. Both demographics will likely compete for similar housing stock.

“Affordability is certainly an issue here,” says Kronick, the think tank director. “For a long time, Toronto [was] a place where you could buy a single-family home in the heart of a city. Decades ago, when other Americans cities were becoming global cities, it hadn’t quite gotten that expensive here yet.”

Sommer believes the sheer amount of building, and the densification taking place, is transforming the city. Restaurants and clubs and theater and music—all of it benefits from the sheer number of new residents. But like any global city, can Toronto continue growing, and growing more expensive, without eventually pushing people out?

“The real debate is, what does ‘egalitarian’ mean?” says Sommer. “Downtown Toronto is a wealthy place, and the cost of living is quite high. It’s more egalitarian than Manhattan now, but we’re closing the gap.”