Thurston County, WA Fire Regulations: Smoke Detectors (2026)

030 governs manufactured and mobile home installation in Thurston County, requiring an installation permit from the resource stewardship department before any manufactured or mobile home is set up as a residence, per subsection A. As part of that same section, subsection B requires every manufactured or mobile home to have an approved smoke detector conforming to and located as prescribed by International Residential Code § R314. Homes that didn't come from the factory with a built-in detector satisfy the rule with a self-contained battery unit or a plug-in detector, chosen specifically so the owner isn't required to cut into walls or otherwise alter the home's structure to install it.

030(A)(3) requires those units to pass a fire safety inspection by the Washington State Department of Labor and Industries' Factory-Assembled Structures Division before the county will issue an installation permit at all. Applicants also submit the personal property tax number and real property tax parcel number for the home and the land where it will sit. 030(A)(4). Permit fees are set by the department's fee schedule and fund the building and fire safety division's operations.