Part 2: The Greenbelt and the Growth of the GTA / by Michael Mazurkiewicz


Presented here is a project undertaken as a theoretical exercise which employs specific strategies for addressing the grandfathered development applications within Ontario’s Greenbelt and for dealing with the rapid urban expansion which is migrating into the surrounding areas.

This article is the second of a three-part series which considers the notion and necessitation of positive-impact developments in relation to Ontario’s Greenbelt. (For necessary context we recommend you read Part One.)


Positive Impact Developments by Necessity

The organizing principle of sustainable development is to ensure today’s needs are met without compromising the ability of future generations to meet their own needs. Achieving sustainability will enable the Earth to continue to support human life. In doing so we consider sustainability in terms of (mitigating) resource consumption and (encouraging) resource salvation.

Through this particular case study we aim to harmonize unique site ecology and positive-impact human developments, beginning by evaluating our needs and subsequently attempting to reduce our carbon use, waste creation, energy use, and capital and operational costs, and increase on-site energy production.


Clear-cut for an Invasive Monoculture

In 2016 we were approached by a developer looking to mitigate the harmful impacts of suburban development. Their selected site – located in East Gwillimbury, Ontario, entirely within the Greenbelt boundary – received a development application in the early 1990s (prior to the implementation of the Greenbelt Act in 2005). This application (and others like it) was grandfathered into the 21st century with an approved 33 estate homes, each with 3,600 square feet on half-acre lots and with no regard for woodland retention or development impact. We were simply asked to improve upon this existing application.

Working with local ecologists we identified key plant species and natural features; what seemed at first to be a healthy greenfield site was comprised largely of the invasive Scotch Pine, having been clear-cut and replanted in the 1950s. As a monoculture the Scotch Pine is even more susceptible to disease and stunts the undergrowth of adjacent plants. In this scenario, when the woodland is dominated by a single conifer its fallen needles will turn the soil acidic and the obstruction of daylight will further deaden the undergrowth. While Scotch Pine is an important commercial species harvested across Ontario, and while it has been naturalized to some extent, it is considered an invasive threat and acts as a reservoir for more than one-hundred pests and diseases.

The remaining areas are comprised of mixed coniferous-deciduous woodlands including several smaller (non-invasive) Red Pine plantations.


Ecologically-informed Site Composition

This ecological analysis informs our re-composition of the site by identifying areas which can be developed to improve the existing ecology. At a site-wide scale, several strategies are proposed to address carbon use, waste production, energy consumption, and costs.

  • Ecologically Sensitive Areas: identifying areas which should be protected/rehabilitated for their unique plant species and natural features (setbacks from creeks and protected upland hardwood forests)

  • Site Transportation: utilizing topography for transportation in conjunction with planned, below-grade services (electricity, water, sewage, and geo-exchange systems) while rejecting cut-and-fill, dead-end, and re-grading strategies

  • Net-positive Energy Dwellings: increasing the total number of dwellings while decreasing their overall ecological impact (33 to 67 units); the dwellings produce energy through roof-mounted solar electric panels which feed into a microgrid for shared power storage; this all-electric microgrid supplies shared electric vehicles, site-to-city transportation, and building comfort systems

  • Waste and Water: constructed wetlands are used to treat black water on-site (an amalgamated approach taking advantage of natural gravity flows to feed localized sewage grids); constructed wetlands also provide a unique habitat for Ontario creatures just as they do in the regions of Cobalt and Brighton, Ontario

  • Public Access and Education: an absolutely essential operational component of this proposal is to ensure the continuous education of its inhabitants and the surrounding county; a Sustainable Living Centre will also house community programs, facilities to support active forest management, and farmers’ markets


It is vital to note that no matter how progressive and ecologically-responsible it may be, a development of this type relies so heavily on two factors: the opportunity to improve a site, and the education, commitment, and diligence of all parties involved. The challenge is not only when and where, but how to develop in a way that makes sense.

Part three of this series presents strategies at the building level to reduce the overall energy demand of the building, reuse nature’s energy passively, and recycle renewable energy actively.