With the Greater Toronto Area's population expected to approach seven million people by 2025, what happened in this neighbourhood could be a blueprint for adding density without being destructive.
"This went from being totally isolated, bedraggled, nobody here ... to the heart of a thriving new neighbourhood," said Greenberg. "This is what we should be striving for."
The area he's talking about is the King-Spadina neighbourhood, in particular the stretch of Wellington Street that runs between Bathurst Street and Spadina Avenue.
Here Wellington Street connects two public squares: Victoria Memorial Park west of Portland Street and Clarence Square on the eastern side of Spadina Avenue. First laid out in the 1830s and based on a streetscape design borrowed from London's west end, the area was home to large industries in the decades to come. For years it was the city's engine of industry but one by one, those factories and warehouses began to close in the post-war years.
A focus on inclusive planning
Greenberg says above all it's the word "transformation" that describes his urban planning work. His book Walking Home is in many ways a defence of cities and their ability to grow and re-define themselves through a bottom-up, almost organic process that requires collaboration between city officials, developers and residents. The book outlines a number of city building lessons learned in a career spent working on projects across North America and in Europe.
From industrial to mixed use
In his book, Greenberg, who collaborated with author and activist Jane Jacobs and worked in the city's planning department, describes the state of his neighbourhood when the redevelopment process began in the 1990s.
"Zoning permitted only industrial uses, vacancies were increasing and property owners began to demolish buildings of irreplaceable heritage value to lower their property taxes. Parking lots by the dozen had appeared in their place."
The first step to spur growth was to strip away restrictive zoning laws that allowed only industrial use. That move sparked mixed-use developments that retained much of the area's old architectural character. Residential buildings along Wellington now sit adjacent to design studio and media companies.
Vacant lots were filled in with businesses and residential buildings and the two public squares were revitalized, allowing them to become the vibrant gathering places they are today. In 1998, Greenberg and his wife moved in to one of the first new residential buildings allowed in the area, at 20 Niagara St.
"New buildings, new neighbours and new businesses are filling in all the voids around us," he writes in Walking Home.
Now 46 per cent of the people who live in the area commute to work by walking.
"When I go out in the morning or evening, there is a pedestrian rush hour," Greenberg told CBC News.
While successful, the process of redeveloping the area wasn't without its challenges. There were fights about getting public money to re-design the two squares and enhance other public spaces, such as the sidewalks. The area is also home to a number of nightclubs, raising complaints about noise and traffic from residents. As the neighbourhood continues to change, many of those nightclubs have closed or changed formats, somewhat reducing the problem of pounding music playing into the early morning hours.
Greenberg says the area's redevelopment could be a case study in how to fill in sections of the city, add density and move toward mixed-use neighbourhoods where people want to live and work. This becomes more crucial with the Greater Toronto Area's population to hit 6.7 million people by 2025.
"We have to expand the menu when we talk about planning," he said.
So what went right in King-Spadina?- Collaboration: Developers, city officials and an active residents' group all had input into how the area took shape. "Instead of having people each playing one note, we're getting chords," said Greenberg.
- Change without ignoring an area's history: Although the neighbourhood is transformed, the basic structure of the streetscape, the location of the two squares and many of the building's facades were retained.
- Willingness of city officials to abandon rigid zoning laws: "On balance, this experiment in deregulation has been an extraordinary success," he writes.
Greenberg points to other areas of Toronto he says haven't had the same success in adding density. For example, the cluster of condo buildings at the mouth of the Humber River, south of the Gardiner Expressway, suffers from "a failure of the imagination," he said.
"There's really no neighbourhood plan, no retail," he said.
Other condo clusters, such the ones at the south end of Bathurst Street near Fort York have had to "play catch up" to achieve mixed use in the area. For example the Concord CityPlace condos had few amenities when they first sprang up. Now a new library has become a centrepiece of the neighbourhood and more retail stores are coming.
Greenberg admits he was at first skeptical CityPlace could evolve into a community. Now he's confident it will. "At the outset I though it would be a disaster," he said. "I had to eat a bit of humble pie."
In the video below, urban planner Ken Greenberg describes in detail the transformation of his neighbourhood.