Austin Celebrates a New Era in Sustainable Building with Hempcrete Code Adoption and Book Launch
By HempBuild Mag
On Friday, July 11, Austinites will gather to celebrate a historic step toward sustainable construction with a special event marking the city’s adoption of hemp-lime—commonly known as “hempcrete”—into the local building code. The celebration, hosted at the Center for Maximum Potential Building Systems (CMPBS) from 6:30–8:30 p.m., will also launch a landmark new book, Hempsteads: Architectural Details for Hemp-Lime Construction by hemp-building pioneer Timothy Callahan of Asheville, NC.
The event comes on the heels of Austin becoming the first major U.S. city to officially adopt Appendix BL of the 2024 International Residential Code, “Hemp-Lime (Hempcrete) Construction.” The new code, which goes into effect July 10, allows hempcrete to be used in permitted residential construction, streamlining the approval process for builders using this carbon-sequestering material.
Hempcrete: A Green Building Breakthrough
Hempcrete is a biocomposite insulation material made from hemp stalk hurds and a lime-based binder. It forms monolithic wall assemblies that are naturally mold- and fire-resistant, vapor-permeable, and highly durable. Importantly, it locks atmospheric carbon into the structure of buildings—an essential step in addressing climate change through the built environment.
“The adoption of hempcrete aligns with our city’s goals to reduce greenhouse gas emissions in the building sector,” said John Lawler, Policy Strategist for the City of Austin. “By embracing hempcrete, we can support local farmers and businesses, foster economic opportunities, and reflect the kind of innovative city we want to be.”
Natural building architect Gayle Borst of Austin-based Stewardship Architecture noted the code change would increase legitimacy and comfort for architects, clients, and inspectors who may have hesitated to use the material. “This change will allow more people to explore healthier, low-carbon homes built with a proven material,” she said.
Austin builders like Carl Gradek, who previously built a two-story permitted hempcrete ADU under an alternative pathway, say this code adoption is a game-changer. “This recognition by the City Council reflects a knowledgeable and forward-thinking approach,” Gradek said. “Austin is leading by example.”