When architect Brian MacKay-Lyons learned one of Nova Scotia’s last remaining octagon-shaped barns was set to be demolished, he bought the building, disassembled the parts and transported them about 140 kilometres south to his property in Lunenburg County. There, he rebuilt the 19th-century barn into what is now a venue for community gatherings and special events.
“There are only three round barns in Nova Scotia,” explains Mr. MacKay-Lyons, founding principal at MacKay-Lyons Sweetapple Architects, a boutique firm with offices in Lunenburg, Halifax and Portland, Ore., and a long list of Canadian and international awards. “So, we had to save this one just because it was such a beautiful and pure example of its kind.”
“Then, a few years later, we found an 1830s one-room schoolhouse near where I had grown up,” he continues. “We saved that, too, and turned it into a dwelling.”
The old barn and schoolhouse, completed in 2009 and 2014, respectively, are now located just metres away from each other on Mr. MacKay-Lyons’s property by the sea. They stand as successful examples of adaptive reuse – an approach in architecture and construction that essentially takes an existing structure and adapts it for another use.
The concept isn’t new. Adaptive reuse of buildings goes back thousands of years, with documented projects that include the conversion of the Pantheon in Rome into a Catholic church in 609. A 2023 book on the subject, Conservation of Urban and Architectural Heritage – Past, Present and Future, highlights early approaches to building restoration during the Italian Renaissance and the French Revolution.
Today, as concern over climate change intensifies and affordable housing becomes scarce in most cities, adaptive reuse – a term coined in the early 1970s – appears to be gaining popularity among builders and policy makers. In the United States, adaptive reuse projects over the past decade have converted former office buildings, hotels, factories, warehouses, health care facilities and entertainment venues into more than 123,000 apartment units, according to an analysis by RentCafé, a Santa Barbara, Calif.-based apartment listing service. Some experts are putting their faith in the trend to solve local housing crises.
A 2017 Deloitte blog post estimates that renovations and adaptive reuse of existing buildings will account for as much as 90 per cent of real estate development in the next decade.
“People have been talking about adaptive reuse for a long time but I think it’s finally coming of age,” Mr. MacKay-Lyons says. “It just makes a lot of sense.”
The benefits from adaptive reuse tick off multiple boxes, says Cory Zurell, a principal at Blackwell Structural Engineers in Toronto and lecturer in the department of civil and environmental engineering at the University of Waterloo.
“One of the benefits is that the buildings that are adaptively reused tend to be these great old buildings with a lot of character, so developers and landlords are able to charge more because people want to be in these buildings,” he says.
“But really, the biggest benefit is from a sustainability standpoint,” Dr. Zurell continues. “The main structure of a building accounts for the majority of its embodied carbon, so if that old building could be modified and renovated to a new use, then all those materials, all that energy that went into building it originally is not being wasted.”
It also means less waste going to landfill. Canada’s construction industry generates one-third of total solid waste produced in the country each year, according to a 2021 discussion paper sponsored in part by Natural Resources Canada. The U.S. Environmental Protection Agency estimates that in 2018, waste from construction and demolition accounted for more than twice the volume of municipal solid waste, or what one might think of as trash, generated nationally that year.
Reducing waste from construction and demolition was one of the goals behind the development of the Alberta community of Blatchford – a five-year-old neighbourhood built on the site of the decommissioned municipal airport in Edmonton. Blatchford development manager Tom Lumsden says the project plan for the community calls for reuse of more than 90 per cent of infrastructure and building material.
“We’re going to keep the air traffic control tower as an amenity within the community and we’re reusing the runway – we’re crushing it and using it as the base for the roads,” he says. “If you walk through Blatchford you’ll see some benches with cobbles on the bottom bench. Those are chunks of runway.”
Adaptive reuse can also improve the sustainability of agricultural and natural landscapes by reducing urban sprawl, Mr. MacKay-Lyons says. In cities such as Toronto, for example, it makes sense to repurpose vacant office buildings into residential structures.
“It’s great because it brings people back into the centre of the city and we know it’s fairly easy to renovate these office buildings into housing – we’ve seen that from all the artists’ lofts in New York that were converted from office buildings,” he says. “There’s also this argument to be made for cultural sustainability and avoiding this cultural amnesia where we become unmoored to any kind of sense of place or belonging.”
Along with these benefits, adaptive reuse projects come with their own set of challenges. Original building features, such as smaller elevators and outmoded window openings, can hamper construction and call for special materials. In some cases, hazardous material may need to be removed.
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Jason Grossi, a Windsor, Ont., architect who recently converted a mid-19th-century stable and a fire station from 1921 into a public library for the township of Sandwich – a historic area along the Detroit River in Windsor – says the challenges of adaptively reusing old structures are also a big part of what makes these projects so rewarding.
With the library project in Sandwich – which opened in 2020 as the John Muir Library – the community wanted the two structures restored to reflect their original state. So Mr. Grossi went down a deep rabbit hole of research.
He made a few surprising discoveries. One in particular shifted the vintage of the stable, which was believed to have been built around 1910 but turned out to be over half a century older.
“When we started to take apart all the masonry to restore it, I noticed there were nail holes on the sheathing that didn’t match the nail holes on the siding and when we started to pull those nails out we saw they were cut nails with forged heads [which were in use until the mid-1800s],” Mr. Grossi recalls. “So we knew this thing was much older than it appeared.”
Armed with this new information, he started to look for other stables in the area built around the same time. He found one in a nearby town – this one had nail hole spacings almost identical to the ones in the stable in Sandwich – and used it to reconstruct what the Sandwich stable might have looked like when it was first built.
The community’s desire to link the two buildings presented another challenge because the barn and fire station did not have the same floor elevation. To address this challenge, Mr. Grossi raised the fire hall floors to bring the building more in line with the stable and connected the two structures with a suspended steel-cable bridge.
The new library has offered residents of Sandwich a way to reconnect with long-forgotten parts of their town’s history, Mr. Grossi says. A number of younger residents who worked on the project even learned new skills – or rather, old skills carried forward from past centuries.
“We actually teamed up with furniture builders in the [local] college and taught them how to build and fabricate historic windows,” Mr. Grossi says. “Some of the young trade apprentices working onsite learned the techniques of masonry restoration.
“It was a hope that if we do that here in Windsor, those skills would actually stay in the community,” he says. “And when another restoration project comes along we would already have the talent here.”