Surrounding Toronto’s City Hall, Nathan Phillips Square serves as the City’s premier civic space. Complete with a reflecting pool, peace garden, sculpture court, playground, permanent stage, and winter ice rink, the design revitalizes the square by creating a robust landscape that is both economically and ecologically sustainable.

Nathan Phillip Square, a large civic plaza at the foot of Toronto’s city hall, was always intended to be a place of gathering. In fact, Finnish architect Viljo Revell ambitiously envisioned not only a square that would house recreating civilians, but one that would host theatrical events, ceremonial processions, even royal greetings.

However, Revell died mid-construction in 1964, and though many of his plans were executed as envisioned, one was not: the three-acre podium concept died alongside Revell, and instead, the city settled for a desert of concrete-block paving. As gray and desolate in June as in December, this elevated platform – actually the roof over ground-floor facilities – had in effect been abandoned long before the City finally closed it off in the 1980s.

In 2007, Hoerr Schaudt, in collaboration with PLANT Architect, Shore Tilbe Irwin + Partners, and Adrian Blackwell Urban Projects, won an international competition to revitalize aging Nathan Phillips Square. Phase one transformed the bleak Podium into a park so versatile, resilient, and hospitable that its aesthetic appeal now has no “off” season. With 40,000 square feet of vegetation, it has become Canada’s largest publicly accessible green roof garden, and it attracts a healthy share of Nathan Phillips Square’s 1.5 million annual visitors. Rows of oblong planting trays lay out a striped tapestry whose right angles set of City Hall’s two curved towers and circular Council Chamber. Specifying tray modules in both four-inch and six-inch depths for different soil profiles enabled Hoerr Schaudt to weave together perennials, bulbs, and grasses that can cope with Toronto’s climatic rigors as well as a broad spectrum of sun exposure.

This botanical mix was composed for abundant variation in seasonal color as well as year-round contrasts of height and texture scaled to the wide-open urban plateau. At ground level, even in winter, an extraordinary tonal range of sedums—more than 15 kinds—maps a calibrated sequence from yellow, orange, and chartreuse in the sunniest southwestern areas to red and purple in the northeast, where Revell’s towers cast giant shadows across the podium.

Design Exchange Awards 2011

Green Roofs for Healthy Cities, Green Roof Award 2011

Canadian Society of Landscape Architects, Honor Award 2011

Toronto Urban Design Award of Excellence 2007

Canadian Architect Award of Excellence 2007