To build a great suburban downtown, Mississauga needs to sweat the details

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This week’s announcement of a “Square One District” for central Mississauga makes big promises. If you believe developer Oxford Properties, it’s a place where “business, life and leisure can come together as one.”

It sounds like a city. But how do you do turn parking lots into a place such as that? It’s a tough question. The fast-growing Toronto region, now at seven million and climbing rapidly, is going to have to solve it.

The Mississauga scheme is in early days. But the latest masterplan and conceptual drawings, by Hariri Pontarini Architects, capture today’s recipe for suburban intensification – mixed up, light on cars and walkable. They also suggest how much work it will take to deliver.

Architect David Pontarini sounded excited about the project when I reached him this week. The developers “are trying to make this a true mixed-use neghbourhood,” he said.

That’s planning jargon for different types of activities: homes, workplaces and retail. Oxford and partners Aimco are hoping to build substantial office space, along with 18,000 homes, over the long term. And because the site is next to the massive Square One mall, there is a lot of retail, something the developers intend to build upon. This combination has been rare in North America. The planning profession for 50 years tried to “segregate” uses, or push them apart.

The second goal, Mr. Pontarini said, “is to create a strong sense of place.” When you unpack the sales pitch with the development – and others of its kind – it comes down to urban activity. In other words, seeing other humans doing a variety of things in a beautiful setting.

The people in the drawings seem to enjoy walking through the square and along “the Strand,” the linear park that centres the development. A shopper in a sari strides over to scoop up potatoes from a farmer’s market booth.

But generating this kind of street life, every day, will require fine-grained decisions about what goes where. Large-format stores and restaurants cannot dominate the neighbourhood. A successful downtown is going to need a blend of small and large retail of all kinds. That sort of thing doesn’t come naturally to large developers seeking predictable returns and secure tenancies. A good city block can’t only serve the bottom line.

It’s encouraging to see a talented architecture firm such as Hariri Pontarini involved here; having designed a series of large-scale master-planned developments in Toronto in the past decade, they understand better than most how to make such a place work.

But to take it all the way, design matters, enormously. What will these streets feel like? That depends on details of architecture and landscape architecture: Paving materials. Planting materials. Street furniture. The language and building materials of these big structures as they hit the street. Mr. Pontarini’s team is imagining architectural variety: some brick at the base, glass with different geometric filigrees up top. All this is laudable.

The question now is whether they’ll deliver. At the human scale, contemporary North American urbanism – especially in car-oriented places such as Mississauga – often falls down. Detail takes time to design. Quality architecture and landscape is pricey. Small shops don’t pay huge rents. And people here want easy access to parking, which needs to be hidden away to create a vibrant cityscape.

There are tensions. The project “is going to be a never-ending attempt to make it feel like the city, and it’s not going to be the city,” said Frank Lewinberg, a partner at the planning firm Urban Strategies, who worked on aspects of this plan. “It has to be a place where people who live in suburban environments feel comfortable.”

“Taking the Pontarini plan and making it real: That’s the challenge that the urban designers and the developers have, and I think they will.”

To do so, everyone involved needs to question their professional assumptions and double down on building something of quality. Places such as this should be centres for the lives of millions of people. They need to be not just adequate, but great; not just visions, but realities in concrete and brick and earth.