Mason County, WA Building Setbacks & Zoning: Structure Height Limits (2026)

Mason County Code Section 17.04.214 sets the building regulations for the Rural Residential 2.5 (RR 2.5) district, the county's smallest rural residential lot tier. Subsection (b) caps building height at thirty-five feet, but exempts agricultural buildings, cell towers, antennas, water tanks, and any necessary structural elements for an otherwise compliant permitted land use from that cap, so a barn or a telecommunications tower is not held to the thirty-five-foot line that governs a house. Subsection (a) pairs the height limit with a four thousand eight hundred square foot maximum footprint, though dwellings and agricultural buildings are excepted from that size cap too.

The identical thirty-five-foot height limit and forty-eight-hundred-square-foot cap repeat at Section 17.04.224 for the RR 5 district and Section 17.04.234 for RR 10, so the same ceiling applies across the county's standard rural residential tiers. Cell towers built under this exception must still be sited under Ordinance No. 5-98, Telecommunication Towers, per Section 17.04.217(a). Because Title 17 zoning is enforced under Mason County Code Chapter 15.13, a structure built over the thirty-five-foot cap without a permitted exception is a development code violation: the county can order a stop-work order, require the structure be brought into compliance, and assess civil fines under Section 15.13.050.