Part 1: The Greenbelt and the Growth of the GTA / by Michael Mazurkiewicz

The environmental crisis is perhaps the most urgent architectural issue of today. In Canada, buildings are responsible for enormous amounts of energy used, resources consumed, and atmospheric emissions. In 2016 our team began developing a strategy for addressing the environmental impact of suburban and rural developments. Our chosen context was the entire Southern Ontario region. Collaborating with developers, municipalities, and ecologists, we first examined Ontario’s ecological treasure: the Greenbelt.

This two-part blog post considers the notion and necessitation of positive-impact developments in relation to Ontario’s Greenbelt.


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What and Why is the Greenbelt?

One of the largest designated greenbelts in the world, Ontario’s Greenbelt is entirely larger than the province of PEI. Home to more than 6,700 farms, 2.1 million fruit trees, and 78 at-risk species, it encompasses the Niagara Escarpment, the Holland Marsh, and the Oak Ridges Moraine. The carbon sequestration of its forests offset 27 million cars annually.

Of enormous importance to Toronto is the encompassed Oak Ridges Moraine which principally recharges streams and rivers in the region by acting as a giant reservoir, and the sand and gravel aquifers filter and purify its water as it eventually flows into Lake Ontario, Lake Simcoe, and Lake Scugog.

In 2005 the McGuinty government introduced the Greenbelt Act, the intent of which is to protect prime agricultural land, heritage sites, and ecologically- and hydrologically-sensitive areas. The Greenbelt itself combats urban sprawl in part by preventing adjacent municipalities (and bedroom communities like Halton, York, and Durham) from re-zoning these areas.

Pre-Greenbelt and Post-Greenbelt Sprawl

While it was created in part to curb sprawl, the Greenbelt is increasingly threatened by the growth of the GTA. For decades Toronto (alongside many cities) experienced classic urban sprawl by developing out beyond boundaries of built-up urban area instead of increasing density. Today the demand for suburban homes and communities persists.

While the Greenbelt Act (2005) retroactively protects some areas from future overdevelopment, it does little to combat the impacts of continued sprawl. Today there are hundreds of development applications within the Greenbelt – many of them grandfathered – which could either be detrimental or beneficial to the region’s ecology. Comparatively, by 2066 downtown Mississauga is estimated to have the same population and density as Toronto today, and the population of the GTA will have doubled entirely.

This continued rise in population is spurred by a combination of immigration and a demand for single-family, high-impact homes. More homes is not necessarily a solution for high housing costs, but a response to growing population and rising demand. The fringes of growth will have a clear impact on the Greenbelt in decades to come.

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Positive-Impact Developments by Necessity

Manifestations of traditional suburban typologies in Southern Ontario include poor regard for context, little integration with nature, bulldozed and paved sites, destruction of valuable land and ecosystems, and – not surprisingly – the perceived embodiment of wealth: a large, sprawling home on an enormous clear-cut property complete with multiple gas-guzzling cars necessary for dreadful daily commutes. This traditional approach to suburban development has catastrophic environmental impacts including loss of productive land, diminished water filtration, and habitat destruction.

How do we ensure these – and decades’ worth of future developments – have a positive environmental impact? The answer begins with understanding why and how the infrastructure of cities and communities interacts with regional ecosystems.


Part Two of this series presents specific strategies for addressing the grandfathered development applications within the Greenbelt and for dealing with the rapid urban expansion which is migrating into the surrounding areas.