This column is an opinion from Hamilton-based writer Sarah Sheehan. For more information on CBC’s Opinion section, please see the FAQ.
Reduce, Reuse, Recycle: Adaptive reuse fits the “three Rs” sustainability mantra, but too often we overlook the green side of architectural conservation.
Whether it’s a neo-Gothic church, a modernist century-old project, or a contemporary glass and steel design, a completed structure has a huge carbon footprint. Tearing down an existing building, dumping it in a landfill, is an astonishing act of conspicuous consumption. And yet, this destructive and extractive approach to Canada’s built heritage has become normalized over generations.
Reusing old buildings is an easy way to reduce our carbon footprint, but first our development thinking needs to be reset.
As Canadians, we can be cavalier about our abundance of resources, and existing buildings are no exception. Our construction industry relies on a cycle of premature obsolescence, demolition and redevelopment. Older buildings are often seen as a liability, while many new developments still operate on a ‘take, make, waste’ model – an extractive model of growth that is the opposite of sustainable.
A colossal amount of waste
Half of global carbon emissions come from extractive industries such as mining; over the past 15 years, emissions have increased the most from the extraction of non-metallic minerals associated with construction, such as sand, clay and gravel. In fact, the demand for concrete is so high that we lack sand.
For Canada, add deforestation and throw away millions of tons of wood wasteincluding old wood, and you have a colossal amount of waste.
Recognizing the initial issues involved in construction allows us to see existing buildings not as future waste, but as valuable reserves of embodied carbon. Also known as embodied emissions or embodied energy, embodied carbon refers to the total energy expended – invested – in the construction of a building, from natural resource extraction, manufacturing and transportation. until the final completion of a new structure.
This carbon investment represents up to 50% of a building’s lifetime greenhouse gas (GHG) emissions, even for buildings constructed with the most sustainable and modern methods and materials.
Embodied carbon was a hot topic in Glasgow last fall, as delegates gathered for the 26th UN Climate Change Conference (COP26), six years after the 21st edition gave us the Paris Agreement .
Alongside the high-level international delegates were members of the Climate Heritage Networka group of sustainability-minded architects and planners like Carl Elefante, who coined the phrase “The greenest building is the one that’s already built”, and Mark Thompson Brandt of MTBA Associates in Ottawa, who often reference to “common sense to recycle buildings.”
A leader in built heritage conservation as a climate action, Brandt has advised federally owned heritage sites in Ottawa, including the House of Commons, the Connaught Building and even 24 Sussex Drive. His company is also behind Building Resilience, an online toolkit for sustainable renovations and rehabilitation of existing buildings. As Brandt said a post-COP26 rally hosted by the National Trust for Canada“Heritage conservation is environmental conservation. It is one and the same thing.”
Built heritage, natural heritage: the climate emergency demands that we tear down the established and artificial divide between natural and built environments for a more holistic view of conservation, heritage and sustainability.
Of course, rethinking the value we place on architecture is something heritage advocates have been doing for decades. Yet the not-so-green status quo persists, based on post-war ideas that value unsustainable consumption. This lingering legacy is a powerful incentive to waste.
Developers and regulators need to catch up
Since World War II, we have taken new developments for granted as a sign of progress and prosperity. Think about the Index of cranes, a simple count of construction sites as a measure of growth. Susan Ross, who teaches at the Azrieli School of Architecture and Planning in Carleton, highlights the growing imbalance: “By the 20th century, architects had completely embraced a real estate process that had made obsolescence its rallying cry, not yet recognizing how unsustainable the cycle of destruction and construction could be.”
Yet Canadians already recognize the value of recycling architecture; it’s developers and regulators who have to catch up.
Across the country, examples of successful adaptive reuse abound. Converted industrial sites like the one in Montreal Factory CHamilton’s cotton factoryand the one in Toronto Distillery District have become centers of power for tourism and culture.
Even places of worship, often seen as purpose-built and hard to sell for reuse, perform brilliantly when repurposed. In Ottawa, there are Bluesfest HQ in a former Westboro church, nestled next to new infill housing. In Saint John, New Brunswick, Cooke Aquaculture has its offices in a beautiful old synagogue. And in Winnipeg, work has begun Augustine Centera hub to encompass art space, childcare and a shelter/drop-in program – reinventing a century-old church for a greener future.
Architecture is a renewable resource. It’s time to stop seeing it through the prism of planned obsolescence.
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