At this year’s Greenbuild Conference and Expo, held Nov. 4–7 in Los Angeles, bio-based building materials took the spotlight — both on the show floor and in one of the conference’s most crowded sessions. As sustainability standards evolve, architects and builders are taking a serious look at hemp along with straw and other plant-based materials not just for their carbon benefits, but also for their non-toxic qualities and fire resistance, increasingly crucial in wildfire-prone California.
Greenbuild — the world’s largest annual event for green building professionals — draws thousands of attendees from architecture, engineering and construction fields, including more than 5,000 architects each year. With the rollout of LEED v5, the newest version of the U.S. Green Building Council’s certification system, biomass-based and mineral building materials are gaining fresh attention as essential tools for meeting embodied carbon goals.
A Well-Attended Conversation on the Bio-Based Future
One of the most talked-about sessions was a bio-based building materials panel, featuring Anthony Dente (Verdant Structural Engineers), Cameron McIntosh (Americhanvre and the Hemp Building Institute), Lindsay Baker(International Living Future Institute), and Massey Burke (California Straw Building Association). The panel was well-attended, reflecting a surge of professional curiosity about materials once seen as niche.
McIntosh emphasized that materials like hemp, straw, and rice hulls are “rapidly, agriculturally renewable,” not horticultural crops (cannabinoid hemp) grown for flowers or oils. “What makes [industrial] hemp cool is that it’s a true agricultural commodity crop,” he said, noting its power to “bridge the divide between rural and urban America.” He added, “Support for American agriculture and increased domestic self-reliance… can begin to help heal that divide. We can talk to both sides.”
From Codes to Construction: New Technical Support
A clear theme at this year’s GreenBuild was the professionalization of bio-based materials, driven by technical testing and new building code pathways.
“At Verdant Structural Engineers, going on 20 years ago, we just wanted to help people get permits for what we considered to be the good stuff,” said Anthony Dente, whose firm led engineering work on the hemp-lime, straw bale, cob and light-straw clay appendices in the International Residential Code (IRC). “Now we have this set of tools that are helping us day in and day out, submitting for permits with what still is and used to be ‘alternative’ systems,” Dente added.
Dente explained that it’s now harder to get appendices adopted at the state and local level than to get them included in the national code. “It’s much more difficult to get a state to adopt an appendix than it is to get an appendix put into the international code,” he said, issuing a call-to-action for professionals to work locally to get hemp-lime and other bio-based building codes recognized locally.
Recent wins include adoption of the hemp-lime appendix by the City of Austin, Texas, and the State of Minnesota — important footholds that make permitting smoother for future projects.