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IRC Commentary Development Updates

Updated: Apr 12, 2023

International Residential Code commentary development for Appendix BA: Hemp-lime (Hempcrete) Construction makes progress.


The Hemp Building Institute (HBI) is proud to discuss the plan and progress for the development of the commentary for the Hemp-lime appendix in the International Residential Code (IRC) that has been accepted by the International Code Council (ICC). We have entered into the small group review portion of our development process which means we are bringing on five more professionals from the hemp building industry that are volunteering their time to review and improve what has been developed. We are also happy to announce our collaboration with the US Hemp Building Association (USHBA) on completing the development process.



IRC Commentary Development Process

In order to create the commentary for the Hemp-lime appendix for the IRC, we are following a similar process to that with which we used to create the initial code language.

  1. Leadership team and consultants develop initial language - The leadership team work with the code consultants to develop the initial language based on existing commentaries, insight from reviewers during the IRC code language development, and the team's expertise.

  2. Small group review and additional language development - A team of experts is brought on to review the initial draft of the language and to help further develop the commentary.

  3. Large industry review and final alterations of the language - A broad team of industry experts reviews what has been developed and suggests final alterations of the language before the document is submitted to the ICC.

  4. Submission of the document to the ICC

The leadership team, made up of Jacob Waddell from the HBI and Mary Dempsey from Mpactful Ventures, wrote the initial language for the commentary taking heavily from commentaries for other natural building materials appendices and comments made by reviewers from the initial code language development. The consultant team then performed the initial review of the document. Anthony Dente and his team at Verdant Structural Engineers reviewed and wrote the sections of the commentary that involved structural engineering concerns. Martin Hammer and David Eisenberg then reviewed the entire commentary offering corrections and writing sections they believed were missing the mark.


We are now entering the 2nd step of the process, the small group review. The small group that has agreed to help with this stage of the process include Cameron McIntosh, Co-Owner of Americhanvre, Matt Marino from Homeland Hempcrete, Tim Callahan from Callahan Designs, and two representatives from the USHBA Board of Directors Alex Sexsmith, Principal at Sexsmith Architects, and Tai Olson, Director of Operations at US Heritage. They are currently reviewing what has been made so far and using their expertise to make suggestions for improvements to the document.


USHBA and USHBF Join Forces with the HBI

The USHBA Board of Directors and HBI President, Jacob Waddell, met to discuss how the organizations could work together to move forward the hemp building industry. The first project the groups are collaborating on is the development of the commentary for the Hemp-lime appendix for the IRC. Two members of the USHBA BOD team joined the small group of reviewers of the commentary, the USHBA agreed to donate $3,000 from the US Hemp Building Foundation(USHBF), and support fundraising efforts towards the goal of $20,000 needed to pay consulting fees and other costs of the commentary development.

Donate to the Commentary Development

The IRC commentary development team continues to make progress, but we need YOUR HELP!!! Please DONATE to the HBI to cover the costs of the commentary development.

To learn more, check out the IRC Commentary Project page.

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