Committee recommends council consider shrinking minimum dwelling-unit area to 120 square feet

At the Building Code Council BFRW committee meeting on April 10, members recommended that the full council consider a package of IBC amendments that would reduce the minimum habitable area for a one-room dwelling unit to 120 square feet, narrow some kitchen clearances to 30 inches where those clearances are not part of an egress route, and strike the separate “efficiency dwelling unit” definition from the draft model code.

Dustin, who introduced the draft on behalf of the tag that developed the language, summarized the process: the tag reviewed RCW 19.27.801 and model code language, merged public proposals into a consensus draft and focused most edits in Section 1208. “We got down to a dwelling unit area down to a 120 square feet,” Dustin said, describing how minimum habitable-space and room-dimension provisions were combined in the proposal.

The change drew technical questions about the example diagram and how the code treats clearances that are also means-of-egress components. Dan Young pressed the committee on long-standing practice in other codes, saying, “Every other code, the IRC, IBC says very clearly that all passageways such as hallways, etcetera, have to be 36 inches.” Micah responded that the building code’s means-of-egress sizing is context-dependent and that a 30-inch kitchen clearance may be acceptable where it is not used as part of an egress path: “You may not be going through your kitchen to access the egress,” he said, explaining why the tag left a 30-inch kitchen clear passage in the figure while relying on chapter-10 egress rules where relevant.

Members discussed whether to add clarifying text or a second diagram showing when a kitchen clearance functions as an egress. Several members recommended leaving the egress-sizing question to chapter 10 references and improving the diagram and user notes so designers understand the limits of the illustration.

The committee also debated removing the distinct definition of an ‘‘efficiency dwelling unit.’’ Angela argued the term was unused in the rest of the code after the draft’s restructuring and that leaving it would cause confusion; some members from jurisdictions that historically used the term urged caution, noting local amendments can reintroduce it. After discussion Angela moved to recommend the amended dwelling-unit-size proposal to the full council; Dan seconded and the motion carried by voice vote.

Next steps: the committee’s recommendation will go to the full Building Code Council for consideration and public hearings as part of the regular code-adoption process. The tag indicated it will refine the diagram and some cross-references before the council package is posted for public review.