In 2024, USHBA removed barriers for residential home projects when a Hemp-Lime (Hempcrete) Appendix BL was published in the 2024 US Model Residential Codes.

Appendix BL will allow use of hemp-lime in buildings up to two stories in regions of low seismic risk prescriptively without engineering. Regions of high risk and taller buildings still fall under the code, but will require an engineered design.

The IRC is a model code for one- and two-family dwellings and townhouses, and is the basis for the residential code in 48 states (except Wisconsin and Arkansas).

US Hemp Building Association has partnered with ARCAT to publish specifier details for hemp-lime (Hempcrete) Thermal Insulation. Architects use guide specs when incorporating a material into a project’s construction bid documents. Specs for hemp-lime wall infill material include technical data, ASTM standards (as developed), performance features and product attributes.

The US Hemp Building Foundation has been approved for the American Institute Architect’s Approved Continuing Education Providers, allowing representatives from the USHBA to provide approved CES presentations to US architects.

Would you like to introduce AIA members to hemp building materials?

Contact Board member Tai Olson to learn more.

What happens when designers and architects think with HempLime as a primary material for design? Parsons New School Healthy Materials Lab researched and collected a handful of engaging projects at a variety of scales, construction methods, and building uses.

The goal for this publication is to create a catalog of precedents to motivate other architects to use hemplime in future projects. With their permission, we redrew their design details to compare the various design and construction methods.