TAG debates embodied-carbon proposals; some members urge caution over cost impacts

During the Sept. 3 meeting the TAG reviewed two petitions addressing embodied carbon in construction: one that emphasizes a whole-building life-cycle assessment (LCA) pathway and another broader package that would add prescriptive and alternative compliance options. Roger and several TAG members noted that, as appendices, these proposals would not create an immediate statewide mandate; jurisdictions would opt in. "Because it is an appendix, we have not made any additional requirements for anybody in the state of Washington so that there is no economic impact," Roger said.

Other members disagreed, saying that once an appendix exists, jurisdictions may adopt it and that initial adoption could impose costs on designers and suppliers unfamiliar with whole-building LCA processes. "I feel like this provision overall is gonna get really tricky," a member said, noting potential short-term costs for small design firms that lack in-house expertise. Several TAG participants emphasized that whole-building LCA, when properly implemented, can identify material optimization that reduces both carbon and cost over the project life cycle; one participant cited project examples where LCAs reduced construction costs.

The TAG did not reach a final numeric determination. Members suggested a conservative approach: mark proposals as cost-increase candidates for the preliminary record while collecting more data during the upcoming hearings. Staff was asked to post proposal documents and background materials to the IBC tag page and to solicit additional data on both short-term construction costs and longer-term life-cycle savings.

Quotes in this article are drawn from the Sept. 3 transcript of the IBC TAG meeting.