Recently Donald W. Davies, PE, SE, and President of Magnusson Klemencic Associates, shared his expertise on fiber optimization and bamboo as a key to minimizing carbon within buildings in the following article:
The events of this year’s COP26 conference in Glasgow, Scotland, are our latest step in trying to act on climate change. Yet even with all of the conference’s pronouncements, responses, and action items, our activities around the global built environment are lagging. It is widely accepted that buildings produce nearly 40% of all greenhouse gases annually. Given the accelerating signs of climate change, how we create and maintain the built environment is critical to finding solutions for where we go next.
Two principles should guide owners, developers, architects, and engineers as they work towards decarbonizing the built environment:
- We can’t manage what we don’t measure, so we need to start with more credible carbon counting of the materials creating our built environment.
- When we build, we need to use materials where they are best suited, and we need to use lower-carbon, rapidly renewable materials to meet our project goals.
On this second point, no single building type or material will allow us to build our way out of our challenges. We need to re-use and renovate what we already have. When we do build new, we need to work with each material for what it does best, creating hybrid building solutions that optimize at every turn. Finally, we need to drive toward lower carbon and carbon sequestering advancements within every material type.
Wood is Good, But It’s Not Enough.
Many are focusing today on mass timber building solutions and more uses of timber pine as a building material. Wood is good, but if we are not careful, we will quickly exhaust this resource faster than we can grow it. Witnessing now-perennial wildfires that impact our forests, our supply of useable timber pine is and will continue shrinking faster than we would like to admit. A forest’s recovery time is also measured in decades, and we don’t have a fast-moving fix when damage is done.
So, what else can we do? We need to optimize our limited resources to buy us more time, and we need to establish other fiber sources within our building systems. If you lean into these ideals, fresh, new, and exciting innovations and solutions emerge.
Optimizing bio-based building solutions is simple. Pay attention to the fibers, and use the strongest, fastest-growing fibers we can reliably mass-produce. “Fiber Optimized Design” should be in every designer’s mind when working with grown materials. Fibers like timber pine are often our focus today because they have predictable properties, are abundant (but not unlimited) in supply, and can be beautiful if left exposed.
But not all timber pine is equal. Multiple species and grades exist, and one must work around the wood’s inherent flaws. Engineered wood products such as glulam beams and mass plywood panels often mix timber species and grades, and work with veneers and pressed laminates to minimize the impacts of board flaws and achieve better use of the wood fibers. But we also need to expand our thinking beyond timber pine to include other rapidly grown fibers that are even stronger and faster-growing.
Timber Bamboo’s Teaming Benefits
Fiber Optimization is about using the best fiber-based material for each load application and using the fiber where its mechanical properties are most appropriate while balancing the carbon and other impacts associated with creating and harvesting the fibers. When two wood species perform the same structurally, we ideally want to specify the faster-growing species since its growth captures atmospheric carbon faster.
Taking this idea farther, we need to go beyond an exclusive use of timber pine. There are multiple options, but nature’s fastest-growing structural fiber—timber bamboo—is a clear front runner. Its mechanical properties match or exceed timber pine, and it grows in a fraction of the time.
Timber bamboos are the super-large species of bamboos with many fascinating properties. It can grow to over 100 feet tall and be harvested annually, growing back the following year. The secret is in its grassy roots, which don’t die and don’t need to be regrown after each harvest. As bamboo’s root structure matures, the above-ground biomass only grows faster and more efficiently if water and nutrients are available to sustain it. As a result, the volume of bamboo fibers grown in four to seven years equals the volume of timber pine fibers grown in 40 to 60 years.
Timber bamboo doesn’t grow in all climates; it favors moist, humid areas closer to the equator, so we will need to diversify where we get our materials from when considering bamboo within engineered wood products. The Southeast regions of the United States, as well as many parts of Central America, the Northern regions of South America, and greater Southeast Asia, all have prime bamboo-growing regions and potential. Some fallow cotton and citrus plantations within the Southern United States have started experimenting with growing timber bamboo, so the opportunity of an American market that grows this material exists, but still is in its infancy. If bio-based solutions are essential to our future built environment, with an unlimited demand for limited resources, the faster we move toward growing more timber bamboo and incorporating timber bamboo fibers into our building systems, the better.
To incorporate timber bamboo into the western-style buildings we build today, it needs to be milled and manufactured into the shapes and forms we are familiar with. And like any engineered “wood” product, it must pass extensive structural and safety tests to conform to building code standards. Timber bamboo products are only now entering the North American markets, and there are only a limited number of companies experimenting with their use. This needs to change, but today one North American company is leading the industry in combining bamboo with other wood fibers for fiber optimized structural alternatives.
BamCore’s Pioneering Advancements
BamCore in Florida is now using bamboo fibers in their products and they have started to make a number of engineered wood products incorporating timber bamboo along with different species of wood including pine, fir and eucalyptus. As I’ve observed this company and the industry they are incubating, they have been taking the fiber optimization steps that others are yet to appreciate or act upon. They are developing the global supply chain to provide timber bamboo within the US, they are experimenting with and advancing the use of fiber-optimized building components with timber bamboo and other fibers in more optimized ways, and they are creating prefabricated building approaches that take advantage of factory automation and precision. Others are working on mass timber building systems with pre-engineered factory automation, but not with more rapidly growing fibers like bamboo within their products, and not with the level of focus that BamCore is bringing to their system innovations. Others will hopefully follow their lead as we need more, not less activity within this space, but it is evident today that BamCore is pioneering the use of bio-based and fiber optimized systems in ways the building industry desperately needs.
Meeting Our Age’s Defining Challenge
Climate change is the defining challenge of our age, and buildings are one of the largest single sources of greenhouse gas emissions. The Carbon Leadership Forum, Architecture 2030, SE 2050, and other groups in the global design community have adopted timeline objectives for decarbonizing the built environment. But these timelines will only be achieved if more options are available.
Hybrid buildings with lower carbon concrete, steel, and bio-based solutions are critical to our future, and we need to apply them across all our design thinking. No single material or system will solve our problems. Still, when considering our bio-based alternatives, fiber-optimized design and the inclusion of more timber bamboo within our building systems seem like obvious next steps. Companies like BamCore today, and others that will hopefully follow, are pioneering the biogenic high performance and fiber optimized building components we need. We need to accelerate this thinking and the use of this material option, and we don’t have time to waste.
Don Davies is President of Magnusson Klemencic Associates (MKA), a 200+ person international award-winning structural and civil engineering firm headquartered in Seattle. He is a leader in promoting urban density and low carbon construction, with projects in more than 19 countries, and up to 105 stories tall.
He is a recognized leader for Embodied Carbon Life Cycle Analysis, including being a founding member of the Carbon Leadership Forum (CLF), an academic and industry collaboration hosted here at the University of Washington. He is also a founding board member of the MKA Foundation, and of Building Transparency.org, who has brought forth the Embodied Carbon in Construction Calculator (EC3).
As an Advisory Board member to the Council on Tall Buildings and Urban Habitat (CTBUH), he has co-authored multiple publications around tall building design, including the Live Cycle Assessment of Tall Building Structural Systems.