"Take 52 Sumach for example," says Les Mallins, the 37-year-old president and CEO of Streetcar Developments, part of a new breed of developers that might make this city a significantly different sort of a place. He's talking about his basic approach to building, and about his life as a developer. Listen. He sounds different. "There's 46 units. Even if everything goes swimmingly, you can't make the kind of money that would change your life on any one project. Not even close."

He compares his situation to other developers, but only because I ask him to. "If you buy a good site and you can get approved for a high rise and you've got 300 units, a $110-million building, you make a decent profit margin, and that's a change-a-person's-life kind of thing." He pauses, and a slight grin comes down the phone line. "Or it's just feeding a beast that wants to accumulate more and more resources."

I've talked to a lot of developers over the years, mostly the big ones.  They refer to their projects as communities, and in a way, they are. They mostly look for prime sites in out-of-the way places, places that aren't neighbourhoods yet, neighbourhoods the City wants to help develop, and so is more generous with the zooming approvals. Then a big podium with two or three towers attached rise out of former parking lots or brownfields. Sometimes the towers become the seeds of new neighbourhoods, as happened a decade or so ago on King Street West. Other times, they become tower ghettoes, like 1960s projects like St James Town, or Flemingdon Park, or Dixon Road. But however they end up, big cities need big developers, and Toronto would be a lesser city without Tridel and Menkes, Empire and Cityzen, Fernbrook and Concert.

But we need to fill in the space between those towers, so many of which have been and still are going up around the city, both on its outskirts and in its core. And so we have what are known as infill developers like Streetcar, Context, Freed and new kids on the block, BSaR. They build mid-rises in the middle of neighbourhoods that already exist, adding to communities rather than trying to create them.

Some infill development is very discreet: houses built in backyards behind other houses. Some is more high profile, like Freed's projects, with names like Fashion House, in the middle of King West. Streetcar falls somewhere in between, mostly standalone projects, in spots where disused commercial and industrial buildings once stood, mostly in Corktown and Riverdale, and all, significantly, on a streetcar line.

Part of the reason Mallins does the kind of developing he does is how he got into the business. "The vast majority of developers are multi-generational," he says. "That would comprise maybe 90 per cent, and 8 per cent of the remainder are people who just have independent wealth or have family that have real estate and can take the excess and become developers. We're in the next 2 per cent. I come from no family wealth. I just made a couple of good-slash-profitable decisions early on."

Like the first property he bought, an old bowling alley at 1852 Queen East. He was an accountant at the time, in 2002, and 1852 Queen East, around Woodbine -- too far east to be Leslieville and too far west to be The Beach -- was not a popular neighbourhood. But he got it for $390,000, converted it to commercial units, and quickly doubled his money. He enjoyed the process, and rolled the profits into another property.

Eight years later, Streetcar's completed 9 buildings, with another 7 under construction, and two more planned for the spring. He employs 18 people, and estimates the company's annual revenue at $100-million, though next year he expects it to be slightly higher, maybe $110 million.

It hasn't always been as easy as that bowling alley. According to both Mallins and Tyler Herschberg, 36, one of the principals at BSaR and a former executive with Empire Communities, the city's cards are still stacked against the mid-sizers. "At 569 King [East], it cost $185,000 to bring a water connection to the building. It would be the same cost for 400 units, and I had 46." The big boys also often have the advantage of building where there are few, if any, neighbours. Mallins didn't report any particular problems in this regard -- perhaps he was being discreet -- but Herschberg, though he says he didn't have much trouble with his first project, 12 Degrees, says not-in-my-backyardism is rife in the parts of the city that are best suited to his sort of buildings.

"There are some good spots in the Beaches," Herschberg says as an example, "but it's tough to make anything happen there as they have real NIMBY ratepayers groups. Same thing with the Annex, and some of the areas near Rosedale and Forest Hill, along the St. Clair corridor. There are tonnes of opportunities on Bloor Street as well. And it's been a battle for people who have been forced way west to make anything happen at all." Herschberg figures King West was as successful as it was because there was no there there to begin with, so no one had anything to worry or complain about. But his chief interest, one he shares with Mallins, is to make already popular, liveable places more so.

"There are places that are nice now," Herschberg says, "and could be a lot nicer, as opposed to going out and taking what's crap now and making it better."

Though Herschberg and his partner, Tarek Sobhi, seem to have taken the long view from the beginning, when Mallins started out, he was just doing what he liked doing, and trying to make it work. "When I started," Mallins says, "I wasn't looking at the city, I was looking at mine and the building next to it."

But then things evolved, patterns emerged and, as has happened in every big city at least since London, neighbourhoods got fleshed in and coalesced.

Bert Archer is Yonge Street's Development Editor.