Wood and the Circular Economy

Naturally Wood

British Columbia’s construction sector is coming full circle—and thinking differently about the environmental impact of materials they specify. They’re looking for ways to change from a ‘take-make-waste’ approach to a more circular economy. One that considers building materials beyond their end-of-life. When designed with this in mind, buildings like biological processes can have a more regenerative life cycle. And naturally, renewable products, such as wood, have an essential role to play in this shift to more enduring, sustainable design.

What is a circular economy?

When thirteen new homeowners move into their townhouses in Vancouver’s Mount Pleasant neighbourhood next year, they’ll be part of the circular economy.

Dubbed Turners Dairy, the project is an adaptive reuse of two century-old wood-frame buildings that evolved from a dairy to other industrial uses such as a luggage factory, book publishing, candle making, and furniture warehouse. A third building was deconstructed, salvaging highly sought-after large Douglas-fir beams. The salvaged old-growth lumber offers a beautiful, durable tight-grain aesthetic. According to one study, it has 12 times less embodied energy than newly manufactured lumber.

The companies behind the salvage efforts, Unbuilders and Heritage Lumber, are making inroads into the circular economy.

Unbuilders, as its name suggests, take timber buildings apart to minimize waste. Its sister company Heritage Lumber is a reclaimed wood brokerage specializing in old-growth Douglas-fir and western red cedar that is salvaged from old buildings, barns, and structures.

Corneil is an example of a growing number of eco-conscious entrepreneurs in the province looking to change how we construct and deconstruct our buildings. They want to see a shift to more regenerative, less wasteful methods, whether it’s single-family homes, multifamily projects, or even larger public and commercial infrastructure. 

But what exactly is meant by the term’ circular economy’? While the principles are not new, the time reflects momentum within the industry to connect sustainable building efforts more seamlessly, according to Paul Shorthouse, an economic development expert. He has been at the forefront of advancing the green and circular economy for over a decade. He serves as managing director for Circular Economy Leadership Canada and led the completion of the recent report Circular Economy & The Built Environment Sector in Canada

What are the input and outputs of a circular economy? 

“The circular economy is about shifting away from the linear model of inputs and outputs. It’s about extracting raw resources with the entire life cycle in mind,” Shorthouse explained. “It’s thinking in a more regenerative way about how you can build products and assets so they last longer, are more durable and repairable over time. It ensures we get the full value out of those resources at the end of their life. It’s about coming full circle and getting materials back into the supply chain for secondary or tertiary use.”

When applied to the built environment sector, Regenerative economic principles can cut waste, recapture lost value, and realize new economic, social, and environmental benefits. When manufacturing building products, this means looking for more circular inputs with lower ecological impacts, such as naturally renewable materials. Regarding outputs, it means maximizing the benefits and minimizing the negative effect of products over their entire lifespan.

Wood, bamboo, hemp, straw, and other agrifiber are naturally renewable, reusable, and biodegradable materials. From this view, sustainably harvested and manufactured naturally renewable products fit well into the circular economy. 

“Timber offers some significant advantages in the circular economy,” Shorthouse explained. “Wood products have an environmental benefit from being able to sequester carbon. They don’t take a huge amount of input energy to produce—trees are grown by sunlight, and manufacturing can be powered using renewable biomass. As a lighter material, it can cut down on transport emissions. And BC has an advantage with a supply of sustainable wood products here at home.”

And mass timber is an opportunity to replace outputs associated with more energy-intensive load-bearing materials. 

Mass timber can be a more sustainable alternative for some of the steel and concrete that goes into our buildings,” added Shorthouse. “It is safe, fire-resistant, and is of comparable strength. It’s lighter weight and adaptable over time. Timber building systems can be disassembled and refurbished with relative ease or used in different ways. Their value can be recaptured at the end of life.”

And factory-built, precisely-manufactured timber construction can better use resources and reduce the number of deliveries to a building site, decreasing overall vehicle emissions. Scraps can be repurposed or used as bioenergy. 

As Shorthouse sees it, considering the embodied energy represented by construction and demolition waste and the implications of continued materials disposal, wood’s natural renewability makes it a valuable building material for a low-carbon future.

You might also like