Federal Way, WA Building Safety: Fire Sprinkler Requirements (2026)

050 opens with a blunt directive that fire sprinkler systems shall be installed, then lists three local triggers layered on top of whatever the International Building Code and International Fire Code already require. First, any occupancy that cannot meet the basic fire flow requirement of the IFC and its Appendix B needs sprinklers, though Group U occupancies are excepted. Second, any occupancy without approved fire department access under IFC 503 needs sprinklers, but Group U buildings and additions to single-unit R3 (one- and two-family) structures are excepted if the fire flow still meets code and access is not unduly compromised, subject to the fire code official's approval.

Third, and most consequential for larger residential and commercial buildings, any occupancy other than Group R3 or Group U triggers mandatory sprinklers once the total floor area within the exterior walls, counting every level including basements, exceeds 5,000 square feet; fire walls under IBC Section 706 cannot be used to carve a building into smaller, unsprinklered sections to dodge that threshold. 2 to reward voluntary sprinklering: buildings protected throughout by an automatic system built to NFPA 13 or NFPA 13R can cut their required fire flow by up to 50 percent, so long as the reduced flow does not drop below 1,500 gallons per minute for the prescribed duration. 050, regardless of size.