Too much empty space is bad for a city. Urbanism thrives on tight corners and complex juxtapositions. An airport runway is the opposite of that: a mile of nothing. How then do you turn a strip of asphalt built for takeoffs and landings into a humming public place, and 370 acres of airfields and factories into a city? That is the question now facing Toronto.

Northcrest Developments is remaking the Downsview Airport lands into a new district called YZD, converting the remnants of aviation into a framework for civic life.

This matters to the city and the country because the site is large and unusual enough to play a major cultural role. Today, the project takes a crucial step: Northcrest has named the American landscape architects Michael Van Valkenburgh Associates (MVVA) to lead the next stage of the transformation.

In a recent interview, MVVA partners Gullivar Shepard and Emily Mueller De Celis sounded humble. “The best places in the world grow organically over time,” Shepard said. “You can’t just open the gates, have a ribbon cutting and hope it’s a great place. It doesn’t work that way.”