Council leans on TAG recommendation to require sprinklers for six‑unit 'multiplex' housing; cost tradeoffs discussed

The State Building Code Council on July 14 reviewed public comments on its proposed multiplex (six‑unit) residential appendix and reinforced the TAG’s recommendation to require sprinkler protection for those buildings, while acknowledging member and public concerns about cost.

Dustin (staff) told the council the TAG considered sprinkler options and recommended requiring a sprinkler system for multiplexes. Roger, who participated in the TAG discussions, said the group “decided to go down this path of sprinklers only and thought that that was the proper way, particularly for this code cycle.”

Council members and industry representatives discussed which sprinkler standard should apply. Dan (TAG/technical speaker) and Angela (council/technical commenter) explained differences among NFPA 13 (commercial), NFPA 13R (residential mid‑rise), and NFPA 13D (very small dwellings), and why the TAG landed on a 13R residential system for these multiplex units. Angela said, “a 13 r system is adequate to protect an apartment,” noting that the 13R coverage is common for multifamily units.

Industry speakers cautioned that sprinkler requirements change project economics. Patrick Hanks of the Building Industry Association of Washington said building under the IRC with a 13R sprinkler can reduce costs compared with full IBC construction, but will increase costs versus an unsprinklered IRC baseline. He told the council that some meter and tap fees vary by water district and that jurisdictions sometimes absorb meter upsizing costs tied to sprinkler demand. Staff and members repeatedly described cost information as jurisdiction‑dependent and said some costs may be offset in practice.

Several written and oral public comments asked for a pathway to allow non‑sprinklered configurations; staff and TAG members said those options were discussed during TAG deliberations and were not advanced for the current cycle. Roger and others said the TAG considered cost and safety tradeoffs and concluded that the sprinkler requirement best balanced outcomes for this cycle, while leaving room to revisit assembly or alternative protections in a future code cycle.

The council did not adopt a final code change at the meeting. Members asked staff to accept amendment proposals and indicated they will post and track proposed amendments for further council consideration at upcoming sessions.