In more ways than one, George Street is a one-way road headed south.
Home to Toronto's largest homeless shelter, part of the street is known as Crack Alley, where dealers feed off the remains of people's lives and lawns are beaten bare by circular walks to nowhere.
"I've travelled around all the other supposed dangerous neighbourhoods in the city," Jonathan Kearns says, "but I never felt so apprehensive as I did when I ventured down George Street."
For most people, a quickened pace, a parting glance over the shoulder and a sigh of relief would mark the end of such a journey. For Mr. Kearns, it was only the beginning.
Since that first nervous stroll a few years ago, he's bought some of the street's most rundown properties, re-imagined it with a rebuilt Seaton House shelter and much-needed student housing, and pitched his vision to officials at city hall and Ryerson University.
For Mr. Kearns, 59-year-old partner at Kearns Mancini Architects, that feeling of apprehension is often the beginning of a big idea.
It was Mr. Kearns and partner Tony Mancini who dreamed up the alliance between their firm and two larger ones, Kuwabara Payne McKenna Blumberg and Montgomery Sisam, that won the international design competition for the current redevelopment of the Centre for Addiction and Mental Health on Queen Street West.
At the other end of the downtown, the hoarding is about to come off a new mixed-use building Kearns Mancini designed in Regent Park, the sprawling public-housing complex also undergoing a ground-up overhaul. Not far from there, the Don Mount Court housing complex was recently rebuilt on one of their designs, and finishing touches are being applied to Rivertowne, part of the same mixed-income complex.
In the shadows of the waterfront Canada Malting silos at the foot of Bathurst Street, Mr. Kearns designed Ireland Park, a stark and stirring monument to famine victims from his birth country who sought refuge in Toronto in the 1840s.
And, the City of Toronto recently announced it has chosen a joint plan by Kearns Mancini and a Vancouver firm for a new visitor centre at Fort York, the effective birthplace of Toronto, which today stands all but hidden under the Gardiner Expressway.
If there is a common thread to be pulled from these and other Kearns Mancini projects, it would be a desire to remove barriers that isolate people and boost public engagement while respecting the city's built heritage.
Mr. Kearns's younger brother Robert, a fellow leader in the Irish-Canadian community who runs a Toronto insurance business, said Mr. Kearns has always valued projects that involve city-building over quick-buck commercial work.
"I think doing something that enriches the weft and weave of the personality of our city is of far greater merit, long term," Robert Kearns says. "It's more bankable than the cheque you might cash from lashing up a hideous condo of tinted glass, which has no design merit and will become the slum of the future."
He attributes his brother's heritage-minded ethos to their upbringing amid the "ancient landscape" of Ireland, particularly in Dublin, a city 1,000 years older than Toronto.
The socially conscious bent of his projects can be traced to his middle-class roots as the son of a civil-servant father who worked in social welfare, and a resourceful mother with a knack for turning their old houses into places of beauty.
"We're not from the manor-born by any means," Robert Kearns says. "We find it very difficult to contemplate a city like Toronto, in a country like Canada in a province like Ontario, where you could have people wanting and hungry and sleeping on the streets. One has to be pro-active in how you deal with that."
Bruce Kuwabara, one of Canada's top architects who has known Mr. Kearns for more than 20 years, gives a similar assessment.
"We're living in a time of incredible consumption, and everything's about economics and everything's about cash flow, and I think he has an ability to stand away from that stuff and feel something that motivates him," Mr. Kuwabara says.
"He's motivated to do his work in a way that I think a lot of architects and a lot of designers aren't. What I'm saying is that he's got a depth of emotion and feeling, and it comes out."
Mr. Kearns, perhaps not surprisingly, offers a more modest explanation of his motives, and is quick to share credit with Mr. Mancini and their staff of 20.
"The activism here has more to do with seeing an opportunity and not seeing anyone else acting on it, and thinking that someone should do something, and just doing it," he says, seated in the firm's airy, post-industrial offices in Liberty Village.
"I think with George Street, I just saw myself having an opportunity as a good citizen of Toronto to pull these energies together for renewal."
A young city by world standards, "Toronto is only beginning to evolve in the design of public space," he says, adding that "the city feels like it was designed by the public works department."
As a result, Mr. Kearns says he feels a duty to step up, as David Pecaut, the city visionary who died in December, encouraged people to do in a long "love letter" to Toronto on the eve of his death.
Mr. Kearns regrets that he never had a chance to meet Mr. Pecaut, but says he took his message to heart.
"This is my city, the city I live in, the city my kids are growing up in," he says, "so I think we should make it better."