Green Design at Evergreen Brick Works: Adaptive Reuse
To be truly sustainable, we will need to upgrade the aging infrastructure of our cities. That means making the most of existing infrastructure, and adaptively reusing older buildings for new purposes, rather than tearing them down and starting over. At Evergreen Brick Works, we reused the buildings left standing whenever possible, drastically reducing the overall carbon footprint of the project.
This site is uniquely positioned. It sits in the heart of the urban centre, next to the busy Don Valley Parkway and Bayview Avenue. The CN and CP rail corridors run nearby. Despite its proximity to these major routes, the Brick Works was far from public transit, and cut off from most people’s mental maps of Toronto. And although it lies within a 10,500-hectare (26,000-acre) ravine system, it lacked a healthy biological landscape, and was compromised by flooding, contamination and waste, and littered with hidden heritage artifacts.
By-products of the brick-making process remained trapped in the soil, including traces of heavy metals, petroleum hydrocarbons, hydraulic oils and silica. This contamination had a major influence on our design decisions.
We avoided exposing the contaminated soil as much as possible. Carefully placing services, such as hydro and sewers, and using low-impact foundations, we kept most of the contaminants safely in place and out of landfills.
Almost 1,700 massive truckloads (more than 36,000 tonnes) of contaminated soil were removed from the site and taken to designated landfill sites at a cost of $1.8 million.
The 16 designated heritage buildings accounted for a third of the total area (16,537 m2 or 177,992 sq.ft.), and included masonry, steel and wood-frame constructions built between the 1880s and 1960s. Decades of neglect and exposure to the elements left many spaces unsuitable for human use, with crumbling walls, contaminated dust, and unsound roofs.
Both inside and outside, extensive graffiti dating back to the mid-1980s covered the walls, ceilings and rooftops. Thousands of individual types, styles and techniques are represented, created by local and international artists. The graffiti is protected under the heritage easement.
Several buildings were filled with asbestos-laden roofing material called transite, a common building material in the 1950s. Lead paint was also present on surfaces across the site.
The preferred option was to repair and keep the transite roofs in order to use less new material. This proved unfeasible from a technical and cost perspective. Instead, the roofs were removed and sent to a designated landfill. Steel columns and trusses with lead paint were encapsulated.
This area is designated a heritage site. Specialists and Ontario Heritage Trust officials documented every nook and cranny, establishing priorities for protection and preservation.
In addition to the heritage designation of the buildings themselves, the complex contained thousands of artifacts in various states of disrepair: kilns, brick presses, pulleys, hoppers, storage bins and conveyors, as well as workers’ chalkboard timetables written in Italian and other mementos from our city-building history.
These artifacts have been largely preserved—some have been adapted to new uses, some archived and stored, and others left in place.
Evergreen Brick Works sits at the centre of Toronto’s massive ravine system—the largest of any city in the world—which carries the tributaries of the city’s urban watersheds, created by the meltwater of receding glaciers 10,000 years ago. They are protected and maintained by Toronto and Region Conservation Authority and the City of Toronto.
When the factory closed its doors, nature slowly began to re-establish itself. With help from community groups and the generosity of concerned Torontonians, the massive adjacent quarry was returned to wetland. On the building site, however, the ecosystem was sick and in distress. Our mission: bring nature back to the area.
The Centre for Green Cities building re-uses the original walls from a one-storey structure known simply as Building 12, a storage area and woodworking shop originally constructed in 1961.
The new foundations rest on steel micropiles, drilled into the ground rather than pounded in. This displaces as little earth as possible, an important consideration on a brownfield site with known soil contamination. It also limits any vibrations that could damage the heritage buildings on-site and disturb neighbouring residential areas.
All but two of the buildings on site were retained. Two buildings (12 and 14) have been made into four-season spaces with full mechanical systems. Buildings 1, 5 and 10b received minor upgrades to accommodate their new uses. Building 15 had its roof removed and a state-of-the-art ice rink system installed. Most of the remaining buildings have been stabilized: full of history and possibility, they await the big ideas of the future.
During construction, a large system of masonry flues, chimney foundations, and kiln floors was discovered beneath the ground. To protect these for future exploration, we placed much of the electrical servicing above ground, and used concrete for the central parking lot to avoid crushing the artifacts from vehicle weight. Infrastructure such as below-grade pipes was carefully located to avoid key areas of archeology.