Research led by Assistant Professor Paul Mayencourt at the UC Berkeley Wood Lab is reshaping how California builds. Partnering with Humboldt County–based Mad River Mass Timber (MRMT), the university has helped establish the state’s first commercial producer of dowel-laminated timber (DLT)—a material that could cut construction emissions, improve forest health and expand affordable housing.
MRMT is now the first vertically integrated mass-timber manufacturer in California, converting waste wood into structural building panels. Unlike conventional lumber, DLT can be produced from small-diameter or weak species such as red fir, hemlock and Ponderosa pine, and even timber damaged by wildfire—resources that previously had little commercial value.
The breakthrough positions California to create a new sustainable manufacturing sector that links forestry management with low-carbon construction and economic development. Because DLT panels are prefabricated for rapid assembly, the technology could also help ease the state’s chronic housing shortage.
This collaboration highlights how UC Berkeley’s College of Environmental Design is translating academic research into large-scale industry change, supporting California’s transition toward greener building practices.
“It’s essential that we reimagine how we build,” says Mayencourt, who holds degrees in architecture and engineering from MIT and the Swiss Federal Institute of Technology in Zurich. He has been working with his Wood Lab colleagues on numerous projects that explore uses for undervalued and underutilized California species, including DLT.
Mass timber panels store carbon for the life of a building, offering a stark contrast to steel and concrete, which are responsible for a large share of global emissions. DLT is particularly sustainable because it uses wooden dowels instead of chemical adhesives, making the panels fully recyclable.
Studies underscore the potential impact: research in Building and Environment found that mass-timber buildings reduced global warming potential by 39–51% compared with concrete and 28–34% compared with steel. Another analysis showed embodied energy of mass timber to be only 23% higher than reinforced concrete, a modest tradeoff for significant carbon savings.
Until MRMT’s launch, California builders relied on imports from Washington and Canada, with long-haul trucking eroding environmental benefits. Locally produced DLT now offers a genuinely low-carbon alternative.
The path from laboratory experiments to a working factory began when fifth-generation sawmill operator George Schmidbauer visited Berkeley’s Wood Lab.
“When I learned about mass timber in college, I knew it was something I wanted to pursue,” says Schmidbauer, now MRMT president. “The market was gaining momentum and there was increasing demand for locally sourced materials to address California’s wildfire and forest health issues.”
Traditional cross-laminated timber plants require massive capital and are ill-suited to California’s lumber mix. After seeing Mayencourt’s small-scale DLT prototypes, Schmidbauer recognized a more practical route.
“Initially, I acted in a consulting capacity, working to help develop the DLT process,” says Mayencourt. “George and I would have weekly calls, sharing ideas and troubleshooting. With a grant received by the Joint Institute for Wood Products Innovation, my Berkeley Wood Lab research associate Jitske Swagemakers and I were designing projects using DLT in the Tahoe region, and George, with his knowledge of the timber industry and supply chain, was figuring out the manufacturing side in Humboldt.”
MRMT ultimately designed its own production machine from standard components and now manufactures floors, roofs, walls and beams for a range of projects. Mayencourt assisted in writing the company’s design guide to align with building codes.
By purchasing material from forest-thinning and tribal land projects, MRMT turns hazardous biomass into valuable products. This approach makes wildfire mitigation financially viable rather than a pure public expense.
“With DLT, we can put lower-value wood into panels and engineer around that species’ reduced structural capacity,” says Schmidbauer. “This means we can connect forest restoration and wildfire mitigation to the low-carbon construction economy in more ways than previously possible.”
The partners are now developing prefabricated DLT kits aimed at rapid construction of affordable multifamily housing. The model blends Schmidbauer’s housing development experience with Berkeley’s design expertise, potentially lowering costs while embedding carbon-sequestering materials into new communities.
As MRMT expands, it is creating jobs in Humboldt County where timber is harvested and processed. “The entire process is optimized for local economic and environmental benefit,” says Schmidbauer.
“Seeing MRMT scale up the manufacture of DLT is exciting.” say Mayencourt. “With one relatively low-tech innovation, we can tackle forest health, wildfire risk, the housing crisis, and struggling rural economies. We can start to fulfill our commitment to reduce greenhouse gas emissions for the future of our planet.”
The initiative aligns with California’s climate goals and national efforts to decarbonize the built environment, which accounts for roughly 40% of global CO₂ emissions. By linking universities, industry and rural communities, the project demonstrates a replicable model for other states seeking to modernize forestry and construction simultaneously.
Originally reported by UC Berkeley in University Of California.
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