Committee advances IRC appendices for alternative materials to CR102

The BFRW Standing Committee of the Building Code Council voted to forward a package of International Residential Code (IRC) appendices that create optional pathways for alternative construction materials to the council's CR102 filing for the 2024 code update. Dustin Curb, SBCC managing director, presented the package and said the IRC TAG revised the appendices to align energy-code references and Washington climate-zone language.

Curb listed the appendices as Appendix BI (light straw-clay), Appendix BJ (straw bale construction), Appendix BK (cob/monolithic adobe) and Appendix BL (hemp-lime). He said the TAG’s edits do not change underlying material standards but make the appendices “ready to adopt” by local jurisdictions; adoption would remain optional and require a local adopting ordinance.

Katy Sheehan asked about process and whether the proposal had the necessary public notice and opportunity for comment; Curb said the TAG heard proponents and industry representatives across multiple meetings and that the next step is drafting a CR102 so the broader code-making public comment process can occur. Chair Roger Heeringa and Angela Haupt asked whether seismic design and energy-code cross-references were addressed; Curb and Haupt said the appendices specify allowable seismic zones and the TAG worked with staff to reference the correct energy-code sections (Heeringa noted SDS/seismic-design references in the draft).

Sheehan moved to file the appendices in the CR102 for Council review and Dan Young seconded. The committee approved the motion by voice vote. The package will be included in the Council’s CR102 filing and subject to the normal public-comment period before any local jurisdiction may adopt the appendices.