Q4 2023: Farm-to-Building Materials

A structural engineer and family farm owner, Don Davies, has a dream to grow farm-to-building materials and reduce embodied carbon in buildings. After 33 years in the engineering field and over a decade as a volunteer in the green building community, Davies has a vision and mission to reduce embodied carbon through better building products. His debut sustainable project is a retrofit of a two-story building in Seattle, WA called, Hubbard’s Corner. The project’s completion will hopefully give insight to builders interested in a greener approach and de-risk the use of sustainable materials in the process.

Products that are making their debut at this job site include: C-Crete Concrete, Sublime Cement, ProZero Bio-Block walls, VersaWorks veneer laminated timber, and HempWool insulation. These new materials haven’t changed the budget by more than 2% compared to using traditional materials, according to the article. The main cost variables have been attributed to surprises within the existing building such as asbestos abatement and utility upgrades. However, experimenting with greener materials can lack efficiency in these groundbreaking projects.

Low-carbon concretes, for instance, need extra time for testing and new systems for storing, shipping, mixing with a volumetric mixer, and placing. Crews also had to use a circular saw rather than a utility knife or serrated blade to cut the HempWool which added time and labor costs. This retrofit project also practices the ‘Boneyard Strategy’ which surveys the existing building’s structural steel for an inventory list of metal fabrication as a collaborative approach to minimize the mill order for new steel.

Overall, Hubbard’s Corner is tracking over 75% below a ‘business as usual’ embodied carbon baseline project. Even with carbon neutral and potentially carbon negative materials, the project will not achieve an embodied carbon negative footprint when construction is complete (there are no carbon negative plumbing materials, etc.). “Zero is hard,” says Davies, “it is an aspiration, but as an industry we are not yet creating true net-zero embodied carbon construction, if we are real with the numbers”. His hope remains that others will follow his lead into lower-carbon construction. [9]

[9] Post, N. M. (2023, September 19). Seattle’s Living Laboratory tests novel low-carbon building materials. Engineering NewsRecord RSS. https://www.enr.com/articles/57095-seattles-living-laboratory-tests-novel-low-carbon-building-materials