Building Safety in Mason County, WA (2026)
4 rules for unincorporated Mason County, Washington.
Verified from official government sources
Fire Sprinkler Requirements
In unincorporated Mason County, new residential and commercial construction must include an automatic fire sprinkler system whenever its fire apparatus access road exceeds 12 percent grade and sits more than 150 feet from where the road meets a county or state right-of-way, under Mason County Code Section 14.17.110. The Mason County fire marshal enforces the standard through plan review and site inspection.
Residential Fire Sprinklers on Mason County Access Roads
Some RestrictionsMason County Code §§ 14.17.110, 14.17.130, 14.18.030
A fire apparatus access road, which is newly constructed or existing, and which is in excess of twelve percent grade, and which is greater than one hundred and fifty feet from a primary access point intersecting with a county or state road right-of-way, to new residential or new commercial construction will require an automatic fire sprinkler system to be installed. ... When buildings are compl...
Childcare Center Rules
In unincorporated Mason County, a commercial day care center is not a by-right use in rural residential zones. Mason County Code Section 17.04.212 lists "commercial day care center" as a Special Permit Required Use in the RR 2.5 district (the same rule repeats for RR 5 and RR 10), so an operator needs a special use permit from the hearing examiner before opening. Section 17.04.217 sets the application requirements and a size threshold for expansions.
Childcare Centers in Unincorporated Mason County
Significant RestrictionsMason County Code §§ 17.04.212(c), 17.04.217(c)-(d)
(c)Special Permit Required Uses. Cemetery, commercial day care center, essential public facility, schools, and community and recreation centers. ... (c)Government operated day care centers, essential public facilities, churches, community centers, and schools may exceed three thousand sq. ft. as approved by a special use permit. ... (d)Essential public facilities, commercial day care centers, a...
Building Permits
Mason County Code Section 14.08.030 supplements IBC/IRC Section 105.1 with specific permit-required categories for the unincorporated county: docks, piers, floats, seawalls, and bulkheads of any construction type, plus park trailers, manufactured housing, commercial structures, and commercial coaches, all needing a building permit before work begins.
Mason County Building Permit Requirements
Some RestrictionsMason County Code § 14.08.030
Section 105.1 is adopted, and supplemented with the following: (1)Permits shall be required for all docks, piers, and floats, excluding: the normal maintenance and repair of boathouses; and floats which are less than 120 square feet, are detached and chain anchored. Permits shall also be required for seawalls, bulkheads, or other similar structures, regardless of type of construction, including...
Plumbing Permits
Unincorporated Mason County regulates plumbing work through the 2021 Uniform Plumbing Code (UPC), adopted by reference at Mason County Code Section 14.04.010(e) under Washington Administrative Code Chapter 51-56. The county excludes the UPC's own Chapter 1, Section 107 appeals provision, routing appeals instead through the county's own building code appeal process.
Mason County Plumbing Permit Code
Some RestrictionsMason County Code § 14.04.010(e)
(e)2021 Edition of the Uniform Plumbing Code as published by the International Association of Plumbing and Mechanical Officials (IAPMO), hereafter the UPC, as adopted in accordance with Washington Administrative Code (WAC) Chapter 51-56. Excluding Chapter 1, Section 107.
All Mason County ordinances
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