Grant County, WA Building Safety: Fire Sprinkler Requirements (2026)

030(1)(j), requires an approved automatic fire sprinkler system built to International Residential Code Appendix U in any new one-family or two-family dwelling or townhouse that meets either of two triggers. 010 imposes on that same use. The second is size and water supply: a dwelling over 3,600 square feet of covered area that cannot meet the fire flow required by NFPA 1142 must sprinkler instead of relying on hydrant flow alone. 010 sets the underlying fire flow standard using NFPA 1142 or the Wildland Urban Interface Code, and then builds in the incentive to sprinkler: installing an NFPA 13D or P2904 residential system cuts the required fire flow by fifty percent, while a commercial NFPA 13 or NFPA 13R system cuts it by seventy-five percent, letting a project with limited water supply or hydrant spacing proceed where it otherwise could not.

040's precedence rule applies if any adopted code conflicts: the first-named code in the list governs. Grant County Development Services keeps the adopted codes on file for public review and administers the sprinkler and fire-flow review as part of ordinary building permitting in the unincorporated area.