Better buildings
November 23, 2021

Coming full circle: wood and the circular economy

How B.C.’s timber construction sector and better building design support a shift toward a circular economy.

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 themselves, can have a more regenerative life cycle. And naturally renewable products, such as wood, have an important role to play in this shift to more enduring, sustainable design.

 

The Wood Innovation and Design Centre is designed with a deep focus on repeatable, reusable, prefabricated construction, key principles for a circular economy. The vast majority of the building—including cross-laminated timber (CLT) panels and glue-laminated timber (glulam) columns and beams—can be disassembled at the end of its functional life and the wood products used in a future structure. | Photo credit: Ema Peter Photography, courtesy of Michael Green Architecture

Circle the wagons

What is a circular economy?

When thirteen new homeowners move into their townhouses in Vancouver’s Mount Pleasant neighbourhood, 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. It has 12 times less embodied energy than newly manufactured lumber, according to one study.

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

Clockwise: Unbuilders deconstruct old Turners Dairy building for reuse. | Photo credit: Unbuilders | Former Turners Dairy building courtesy of Unbuilders | Rendering of new Turners Dairy interior courtesy of AMC Project Development

Turner Dairy Development

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 term reflects momentum within the industry to more seamlessly connect sustainable building efforts, according to Paul Shorthouse, an economic development expert who 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.

Worker disassembling timber building. | Photo credit: Unbuilders

Unbuilders at work
A winning pitch

If you unbuild it, they will come

Circular thinking is coming to prime time. Even CBC’s Dragon’s Den recognized the potential in the lumber salvaging business. Watch Unbuilders’ winning pitch.

RUNNING CIRCLES

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. 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,” Shorthouse explains. 

Regenerative economic principles, when applied to the built environment sector, 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 that have lower environmental impacts, such as naturally renewable materials. When it comes to outputs, it means maximizing the benefits and minimizing the negative impact of products over their entire lifespan.

Forest harvesting in Gordon River, B.C. | Photo credit: Nik West

Forest harvesting operation by CoastFibre in Gordon River, BC

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. 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 B.C. has an advantage with a supply of sustainable wood products here at home,” Shorthouse further explained.

Lumber drying stacks. | Photo credit: Nik West

Lumber stacked for air drying.

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. 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 re-captured at the end of life,” adds Shorthouse. 

And factory-built, precisely-manufactured timber construction can make better use of resources and reduce the number of deliveries to a building site, in turn 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 an effective building material for a low carbon future.

Worker using bridge crane during CLT panel fabrication. | Photo credit: Swanky Photography

Interior daytime view of worker using bridge crane during CLT panel (cross laminated timber) fabrication process
Winner's Circle

B.C.'s home advantage when it comes to building a circular economy

“Timber offers some significant advantages in the circular economy. 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 B.C. has an advantage with a supply of sustainable wood products here at home,” explained Paul Shorthouse, managing director for Circular Economy Leadership Canada and led the completion of the recent report Circular economy & the built environment sector in Canada.

 

A WOOD FUTURE

Four ways wood can support a circular economy

Icon of hand holding a tree seedling

Naturally renewable, durable and long lasting

Wood is a resilient, naturally renewable material that can provide decades, even centuries, of service when properly maintained. Ancient wood buildings continue to stand including 8th-century Japanese temples, 11th-century Norwegian stave churches, and the many medieval post-and-beam structures of England and Europe. And wood is one of the few structural building materials we can grow using the sun while absorbing harmful CO₂ emissions from our atmosphere. As trees photosynthesize, they absorb carbon dioxide from the atmosphere, and in turn storing carbon in wood products.

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Waste reduction and lower emissions

Building with wood can help reduce on-site construction waste through factory-built, computerized prefabrication which can optimize assembly and streamline on-site erection. The use of these manufacturing technologies can complement the environmental benefits of prefabricated timber systems, resulting in higher productivity (e.g. labour, materials), fewer change orders during construction, and less overall waste. Wood products are responsible for lower air and water pollution and have less embodied carbon than other commonly used building materials.

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Salvage and adaptive reuse

Wood is a material well-suited to reuse, whether through the adaptive reuse of an existing structure or through deconstruction and disassembly. In particular, longstanding solid, heavy timber in existing buildings and structures is sought after for its durability and strength, along with its aesthetic beauty and historic significance. Due to its rising value, a growing number of companies specialize in the deconstruction and reuse of this type of timber.

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Deconstruction and disassembly

Wood is well suited to deconstruction and disassembly when a building’s original service life ends. Modern wood buildings can be designed from modular components that can be refurbished as required or remanufactured into new products. For instance, structural elements might be disassembled and set into new configurations over time or wood floors might be deconstructed and used for panelling.

GOING TO PIECES

Timber-built industrial building designed for disassembly

StructureCraft, an engineer-led fabricator of innovative timber structures, has set a new standard in industrial wood building design. The company’s 4,700 square-metre manufacturing facility showcases new levels of engineering efficiency for industrial buildings, combining a variety of mass timber and engineered wood products, including dowel-laminated timber (DLT), laminated strand lumber (LSL), nail-laminated timber (NLT), and glue-laminated timber (glulam). To demonstrate the flexibility of mass timber in industrial buildings, StructureCraft designed the entire building as a demountable structure, providing flexibility to expand or move the facility to an entirely new location. 

The erection of the timber superstructure commenced on a Monday, and the crew had the entire building installed by that same Friday. In just one week, all four walls and the roof were installed. The building was planned according to principles of design for deconstruction and reuse.

 

Photo credit: Calvin Owen Jones, courtesy of StructureCraft

Bits and pieces

How wood salvage, reuse and design for disassembly (DfD/A) supports a circular economy

Salvaging timber for reuse is already showing promising signs that it is more than financially viable, representing a sizable boost to local economies.

“The economic incentive is becoming clear. With the old model of ‘take-make-waste’ we’re leaving money on the table. We need to fix that and therein lies the opportunity with a circular economy,” said George Patrick Richard Benson, senior manager, Economic Transformation Decarbonization & the Just Transition at the Vancouver Economic Commission. 

2020 report, co-authored by the Vancouver Economic Commission, Unbuilders, and the British Columbia Institute of Technology, found that at current valuations, the estimated volume of salvageable wood in Metro Vancouver across the 780+ residential demolitions is worth approximately $340 million a year.

Beyond salvage, design for disassembly (DfD/A) in B.C. and Canada’s building sector is growing. While pick-up has been gradual, there are examples that are helping lay the groundwork for the broader industry. By definition, DfD/A is the design of buildings that anticipates future changes and dismantlement (in part or whole) for recovery of systems, components, and materials. It means much of the building components can be re-used as efficiently as possible at the end of their lifespan, avoiding demolition and diverting landfill waste, and reducing pressures on natural resources. 

While not yet mainstream, both Shorthouse and Benson explained there is momentum for DfD/A and circular construction principles in the province and across Canada.

CK Choi Building | Built in 1996 at The University of British Columbia is an early example and is recognized for extensive material salvage and reuse, in addition to applying principles of DfD/A. The project uses reusable components and a modular design throughout. Salvaged heavy timbers provided 60 per cent of the primary wood structure. Over 50 per cent of the building’s materials are examples of reuse or come from recycled sources. This includes steel, plywood, framing timber and doors. | Photo credit: Don Erhardt 

Interior daytime view of brightly lit UBC CK Choi Building atrium showing three storey glass expanse, Douglas-Fir Glue-laminated timber (Glulam) and Solid-sawn heavy timbers; much of which was salvaged from the 1940s Armoury building

The Wood Innovation and Design Centre, a more recent example, is designed with a deep focus on repeatable, reusable, prefabricated construction. It features wood floor slabs made of overlapping panels of 3- and 5-layer CLT joined together with adhesives and a mesh connector, reducing the amount of concrete needed and making much of the structure easier to disassemble and reuse. In fact, the vast majority of the building—including CLT panels and glulam timber columns and beams—can be disassembled at the end of its functional life, and the wood products used in a future structure. 

MEC, the B.C.-headquartered outdoor equipment retailer with long-standing ecofriendly roots, incorporated features into some of their stores’ design and construction that favour circular principles, and in some cases future reuse and recycling. This includes exposed timber structural framing with bolted connections and timber decks that are screwed down, making disassembly and reuse easier. And as a general rule, mass timber is a material well-suited to reuse, a material MEC has used in a large percentage of its stores across the country, including its Vancouver flagship store. Along with mass timber, the company has made a commitment to minimizing the environmental impacts of all its retail outlets.

MEC flagship store | Photo credit: Michael Elkan Photography

MEC Flagship Store expansive interior featuring wood and mass timber construction
Adaptive reuse

Old and new unite in the circular economy

Adaptive reuse is a foundational component to a more circular economy. Old and new unite in this century-old historic timber warehouse to be topped with a four-storey mass timber addition of modern commercial offices. 837 Beatty Street is an existing three-storey former warehouse located in downtown Vancouver and is part of the distinctive Block 68 collection of historic warehouses. This Edwardian industrial heritage building constructed in 1911 was part of the early twentieth-century building boom that saw numerous warehouses constructed near False Creek across the once Canadian Pacific Railway’s Yaletown landholdings. 


Rendering courtesy of office of mcfarlane biggar architects + designers inc.

SQUARE THE CIRCLE

How can process optimization of wood construction support a circular economy?

To fully realize a circular economy, and timber’s potential contribution, experts point to the growing need to boost optimization across the entire industry, with each player in the supply chain working together with greater integration.

“Optimization tools like building information modelling (BIM), modular construction, the circular economy and mass timber—all of these components are incredibly synergistic,” said Benson. Thinking of a building like a kit-of-parts can not only cut waste during on-site construction, it makes it easier for a building to be disassembled or adapted to new uses, and enables an entire industry to collaborate more effectively,” he adds. 

A growing number of B.C.-based projects, along with their design teams, are helping advance the optimization of mass timber construction. This includes just-in-time construction and digital technologies. 

BIM and virtual design and construction (VDC), along with digital twins, played a central role in the design of one of the world’s tallest wood buildings, Brock Commons Tallwood House. From design modelling through to construction modelling for onsite assembly, the design team leveraged the full capacity of these tools to test, troubleshoot, and ultimately streamline the entire construction process end-to-end. In addition to cutting waste and streamlining manufacturing, this innovative effort by B.C.’s building sector to assemble the tall wood tower as a kit-of-parts makes the building easier to deconstruct and repurpose at the end of its life. 

Brock Commons Tallwood House prefabricated just-in-time mass timber construction. | Photo credit: KK Law | Renderings courtesy of CadMakers Inc. 

BrockCommonsVDC

A number of other mass timber projects are also showcasing what is possible when it comes to optimization of prefabricated timber construction1 Lonsdale Avenueconstructed entirely out of CLT and glulam, made use of advanced BIM and virtual design tools helping to mitigate the challenges of a zero lot line. When it comes to the circular economy, the project shows how renewable building materials—in this case CLT—can be used as a firewall in place of more energy-intensive materials. This digital approach also helps achieve precise airtight construction, critical to achieving a Passive House Certification. 

A 3D model of the mass timber components of 1 Lonsdale Avenue. | Photo credit: KK Law

Open laptop with the plans for a wood building design showing on the screen

B.C.-based companies Naikoon Contracting Ltd., Hemsworth Architecture, Timber Engineering, MCW Consultants and Peel Passive House worked together to leverage the benefits of these digital tools fully. Team members credit new, more collaborative methods as critical to the collective success of such mass timber projects. A virtual build—testing an entire assembly sequence using computer software—prior to starting work on site minimized errors and cut waste while speeding up construction schedules.

1 Lonsdale Avenue virtual model. | Rendering courtesy of Naikoon Contracting Ltd.

1 Lonsdale Avenue Commercial Building Virtual Model
COMING FULL CIRCLE

Where do we go from here?

Shifting to a circular economy is not without its challenges. It requires significant coordination on the part of consumers and businesses, governments, and industry to make the change from a ‘take-make-waste’ approach to more circular, regenerative methods.

Made-in-B.C. timber products have an important role to play and momentum is mounting, according to Benson. Continued focus is needed on waste reduction; optimization; digital technologies; and design for durability, disassembly, and reuse. 

And for the province, the solution is at our back door. B.C.’s sustainably managed forests mean we can reduce our dependence on energy-intensive and non-renewable materials from afar while stimulating greener jobs here at home.

CLT panels on a flat-bed truck being lifted into place by a crane for installation at 1 Lonsdale Avenue. | Photo credit: KK Law

CLT panels on a flat-bed truck being lifted into place by a crane for installation. Photo credit: KK Law.