We are witnessing a renaissance of a building material that is strong, light, flexible, lasts hundreds of years and benefits both physical and mental human health. During production, it can restore natural landscapes, create habitats for plants and animals and employ millions of people. Essentially a solar-powered 3D printer, the “technology” pulls CO2 from the atmosphere and converts it into a variety of building materials that can replace polluting alternatives such as concrete, aluminum, steel or plastic. This technology is the tree.
Cutting-edge engineering developments now allow us to build wood structures taller than 25 storeys that can be erected faster, at less cost and just as safely as their concrete and steel counterparts, while sequestering millions of tons of carbon instead of producing it. New perspectives on traditional and Indigenous knowledge offer synergies between urban and rural communities, and new sourcing relationships with sustainable wood producers make it possible to procure “good” wood that protects forests and communities, locally and globally.
But wood isn’t foolproof. Last year, IKEA came under fire for manufacturing some of its furniture with illegally harvested timber from a Ukrainian supplier. At the height of the pandemic, increasing lumber prices fuelled illegal old-growth “tree poaching” in B.C., and newly completed benches in Oslo were removed after public outcry ensued with questions about the source of FSC-certified tropical wood.
These stories are not uncommon. Increasingly, specifiers are required to know where – and how – wood is produced. Choosing wood that actually delivers benefits to the climate and forests can be challenging. It requires understanding the supply chain, how each forest is managed, how communities are impacted and in what ways the climate has been altered by consumer choices. Currently, this is very difficult to measure given the massive complexity of global supply chains which have sought to produce efficiency often at the expense of transparency.
As an architect who loves wood and forests, I have been wrestling with this challenge for decades, bringing hundreds of forest conservationists, designers, researchers, clients and industry leaders to the table over the past decade to better understand what might make wood truly “sustainable.”
How do we get there?
It has quickly become apparent that we need some kind of industry tool for assessing all of the various wood choices available to us. It is not enough to simply look at the final certification and sequestered carbon in a wood choice. What’s required is a deep dive into all of the possible criteria linked to the material. The main challenge with determining whether the wood used by a project is sustainable is that it depends on the availability of information. Also, we need to be asking the right questions to get the right answers about whatever wood might be chosen. The capacity to identify the right wood choice for a project rests in our ability to pin down the term “sustainable.”
We need to know where our wood is coming from, how the forest it came from has been managed, how communities are impacted and in what ways the climate has been altered by our choices.
Sustainability should be assessed based on forest impact, socioeconomic integrity, carbon storage and life-cycle comparisons. Engaging with the complete forest ecosystem and production system of wood products must be the foundation of a sustainable sourcing strategy.
We worked with members of the Wood at Work community to develop a framework that could help clients, architects, procurement managers, contractors, fabricators and suppliers navigate the sustainability benefits of wood. As a result, we found eight pathways that can be used at both project and policy levels. Like any list or framework, these are not fully comprehensive, but rather are flexible and are meant to be adapted to specific uses. They are as follows:
Pathway 1: Forest Certification
Choosing a wood that is certified is a good first step to help reduce deforestation, protect high conservation values, strengthen biodiversity and bolster ecosystem integrity. This general screening tool uses third-party audits to check that specific practices and chains of custody produce sustainable outcomes for forests. Canada has the most third-party certified forests in the world – 36 per cent of all globally certified forests – with over 75 per cent of managed forest lands having some level of certification.
But certification is often critiqued for “greenwashing” – not going far enough in terms of promoting healthy forests and forest communities, and not providing rigorous audits of practices or sourcing in some contexts. Moreover, certified wood can be difficult to find, can be more expensive and does not always specify a single origin, so consumers do not know where the wood is coming from. When certification is combined with other pathways, however, a robust framework begins to emerge.
Pathway 2: Social Forestry
Local people and communities with a vested interest in their forests often have been found to be the best stewards of forests in different contexts around the world, leading many national governments to delegate management responsibilities to local peoples. “Social forestry” engages local people and communities to generate profits through harvesting and selling wood, improving rural livelihoods and providing an incentive to keep forests standing. This type of management incentivizes local groups to sustainably manage and protect valuable forests from degradation and conversion to other land uses. Wood products from community forest enterprises (CFEs) can offer some of the highest sustainability benefits per unit of wood, owing to the often high conservation value of these managed forests. And CFEs are not limited to the tropics; many can be found in Canada (for instance, through the B.C. Community Forest Association), the U.S. and Europe.
While there are thousands of CFEs around the world, sourcing directly from them can be difficult. Thankfully, many distributors have built relationships with these communities to provide vital logistical support in the supply chain, such as Evergreen Forest Products in Long Island, NY, or Precious Woods in Europe.
Pathway 3: Species and Grade Selection
Often, one or two species take center stage for a given purpose, which can lead to imbalanced demand, overharvesting and monocultures. Spreading demand across a wider range of species or grades can redistribute pressure on forests and provide incentives for diversified afforestation.
Specifying lesser-known species (LKS) and lower grades of timber conserves carbon and biodiversity in forests, strengthens business models of managed forests and creates new opportunities for community stakeholders. This pathway offers economic incentives for low-waste practices that diversify the pressure on natural forests, while utilizing more of each tree that is harvested. Examples include LKS such as black locust (temperate) or pucte (tropical), as well as “character” and “calamity” wood (blighted or burnt) with a reduced grade but perfectly serviceable performance. Diversifying timber plantations also can reduce the risk of damage from pests, extreme weather and climate change.
The use of LKS and lower grades is often limited by preexisting technical specifications, general unfamiliarity and supply concerns, but many examples are available, including Whole Forest, which makes countertops, tabletops and parquet flooring from LKS and mixed species timber, and FSC Denmark, which promotes projects featuring LKS in urban applications. Utilizing a wood species without a thorough understanding of its geographical distribution and lifecycle can have unforeseen consequences, so it’s important to consult with forest professionals and suppliers when using these types of wood.
Pathway 4: Strategic Geography
Sourcing wood from a country, region or municipality with a good track record of sustainable practices strengthens the systemic benefits. Building on the idea of “jurisdictional approaches,” wood sourced using the Strategic Geography (SG) pathway is likely to promote biodiversity, the environment and the local economy.
SG showcases and rewards best practices in sustainable forest management while building regional recognition and rewarding governments (at all levels) for implementing policies and enforcement that protect forests. It penalizes the illegal operations, poaching and corruption that continue to cause deforestation. Evidence and indicators allow consumers to choose geographies that are effectively managing forest areas and distributing benefits to local people, while avoiding areas with a recent history of exploitation and poor governance. In this way, the market rewards conservation and penalizes deforestation.
Pathway 5: Local and Urban Wood
When trees in urban areas die or need to be removed, more often than not they are disposed of, chipped or even burned, because systems are not in place to process them. According to the NYC Parks Department, an average of 30,000 tons of “wood waste” is generated annually from trees in the five boroughs. This astounding volume is mostly chipped, and the stored atmospheric CO2 is quickly released back into the atmosphere.
Forests growing near cities also produce wood that may be available through local sawmills and suppliers. There is currently a renaissance in small sawmill operations that process local and urban wood such as Epilogue Lumber in Portland, SawmillSid in Toronto, Baltimore Wood Project in Baltimore, Angel City Lumber in Los Angeles and City Bench in New Haven. This type of small business can play an important role in local innovation ecosystems, along with providing employment and training opportunities.
Pathway 6: Reuse and Long Life
History shows that wood can remain in service for generations, and can be reused in a variety of ways, from structure to structure, over hundreds or even thousands of years. As long as wood is not burned or decomposed, it stores atmospheric carbon and thus slows climate change. Reusing wood not only retains the carbon storage of the material but it is also associated with quality local employment and manufacturing, predominantly serving customers who are seeking sustainable and unique wood solutions.
Selecting reclaimed wood products (upcycling, repurposing, recycling, etc.) and designing structures that can be disassembled and used again are strategies that extend the life of wood products. Design for reuse will result in systems and standards (components, connections, dimensions, etc.) that make reusing wood simple and cost effective.
All layers of the built environment can be composed of demountable components that can be reconfigured, especially in a future where energy, materials and carbon storage all have high value. Sourcing examples include: Tri-Lox, The Hudson Company and Sawkill Lumber Co. in Brooklyn; Unbuilders in Vancouver; Brick + Board in Baltimore; and Good Wood and TerraMai in Oregon.
Pathway 7: High-Efficiency Production
Going from forest to board to useful building component requires a wide range of tools and processes, each generating wood waste, consuming energy and emitting CO2. Refining these tools and processes can reduce waste and forest impacts by getting more of each tree into a long-lived wood product. “Efficiency ratios” – the specific percentage of wood material that makes it from the forest into a long-lived building – are impacted by everything from tree-felling protocols to the industrial machines that can join smaller pieces of wood into large mass timber elements. A detailed assessment of efficiency also includes energy requirements for kiln drying and transportation, although these tend to be a much smaller contribution to the net carbon footprint.
High-efficiency wood products reduce carbon emissions associated with wood waste at all stages of the harvest and manufacturing process. Improved efficiency also can reduce pressure on forests and requires less land because less wood is wasted per structural unit.
Improvements in efficiency have some drawbacks. Products that use wood volume efficiently may use extra chemical adhesives or energy inputs in manufacturing, such as oriented strand board (OSB). Many of these elements or comparisons can be identified through Environmental Product or Health Product Declarations.
High-efficiency production can be supported by solar kilns, fossil-free freight, using minimally processed wood (e.g., WholeTrees Structures) and implementing mass timber (e.g., Nordic Structures Envirolam) or mass plywood panels.
Pathway 8: Net Carbon Accounting
Calculating an accurate, comprehensive carbon footprint for a wood product is very challenging, and there are few ready-made tools to assist specifiers or end users. Meanwhile, this calculation is the cornerstone of any valid Life Cycle Assessment (LCA) that includes wood components. Factors to consider include the complete spectrum of forestry practices, production processes, transportation and manufacturing (i.e., stages A1-A3). Importantly, this also must include land-use factors that may add carbon costs such as the “carbon opportunity cost” of productive landscapes and the possible “carbon debt” incurred by the difference in carbon uptake between the mature (removed) trees and the smaller ones that will take their place. Conversely, it should also include the value added to forest conservation schemes, such as the WholeForest model, which Peter Pinchot, CEO, explains: “Timber is the reason this rural community is able to conserve 10,000 ha of primary tropical forest. Without the sale of timber products, the forest would be reduced to cattle pasture, like the surrounding landscape. We are able to ascribe a specific carbon value to each board foot of wood that our customer uses.”
A systems-thinking lens is vital to account for unforeseen consequences and counterintuitive behaviors; for example, increased demand for mass timber buildings could have either negative or positive impacts on forests, depending on how and where that wood is sourced. In-depth analysis can determine the net climate impact so that wood products can be compared more accurately to alternatives like steel and concrete construction.
While complete tools and guidance for net carbon accounting are almost non-existent, some helpful examples include: Embodied Carbon in Construction Calculator, Whole Forest Embodied Carbon calculation, NRCan low-carbon assets through lifecycle assessment initiative, Gestimat, PAS 2080.
Strategic sourcing is the key to realizing the complete climatic and environmental benefits of building with wood, which – when poorly managed – can drive deforestation and emit large amounts of carbon. The Cities4Forests publication, “Sustainable Wood for Cities,” combines the latest insights from research and practice to help consumers (cities, individuals or industry specifiers) choose and source wood products that have a measurable positive impact on climate and forests. Our work at Cities4Forests shows that simply engaging stakeholders in this conversation changes the way they think about wood, forests and climate. There is something about wood that allows it to become personal. We see it, we feel it and we hear its stories. This may be the untapped superpower of wood. It can change our relationship with both forests and
even our most urban built environments.
Scott Francisco, founder and director of Pilot Projects, is a designer and systems thinker with a focus on infrastructure that supports long-term cultural goals in cities, organizations and ecosystems. Francisco has taught at the McGill School of Architecture, Parsons The New School for Design, Stanford in New York and other universities. He holds architecture degrees from the University of Toronto and MIT.