In June 2025, the City of Phoenix, AZ adopted the 2024 International Residential Code (IRC) along with a handful of natural-building appendices including Appendix BL, Hemp Lime (Hempcrete) Construction. But as far as anyone in the hemp building industry can tell, it went largely unreported.

Over the past year, nine hemp-based building material manufacturers got the chance to take part in a program the US hemp industry has needed for a long time: the creation of standardized, third-party test data required by U.S. building codes and permitting agencies.

Minnesota appears to be the first US state on the path to adopting the newest official residential building codes featuring plant-based building materials after a July 15 hearing in St. Paul.

A new book of architectural details for hemp-lime construction will be published in May, written by a pioneering US hempcrete builder who helped co-author the hemp-lime appendix published for the first time in the 2024 International Residential Codes.

The city of Austin, TX on April 10  officially adopted hempline (hempcrete) in the city’s Building Technical Codes as an innovative building material to be used in local construction. 

Homeowners returning to their burned-out homes in southern California are facing the painful consequences of the US construction industry’s reliance on cheap plastics and petroleum-based building materials: Not only are these materials easily combusted in a wildfire, but they leave behind a toxic soup that has polluted waterways and poisoned air quality.