Building Setbacks & Zoning in Mason County, WA (2026)
3 rules for unincorporated Mason County, Washington.
Verified from official government sources
Setback Rules
In unincorporated Mason County's Rural Residential 2.5 zone, Mason County Code Section 17.04.213 sets the front yard setback at twenty-five feet and the side and rear yard setback at twenty feet for a house and its accessory buildings, rising to fifty feet for agricultural or home-occupation accessory structures, with a narrower side yard allowed on lots under one hundred feet wide.
Yard Setbacks in Unincorporated Mason County
Some RestrictionsMason County Code § 17.04.213(c)-(d)
(c)Front Yard Setback. Twenty-five feet.(d)Side and Rear Yard Setbacks. Side and rear yard setbacks for the residential dwelling and accessory building is twenty feet, and for accessory structures used for agricultural purposes or home occupations is fifty feet. Exception to the side yard standard is allowed on a parcel with a lot width up to one hundred feet at the building site: the required ...
Structure Height Limits
In unincorporated Mason County's Rural Residential 2.5 zone, Mason County Code Section 17.04.214(b) caps residential structures at thirty-five feet in height, with exceptions for agricultural buildings, cell towers, antennas, water tanks, and structural elements necessary for an otherwise compliant permitted use. The same section caps most non-dwelling buildings at forty-eight hundred square feet.
Building Height Limits in Unincorporated Mason County
Some RestrictionsMason County Code § 17.04.214(a)-(b)
(a)Size. Four thousand eight hundred square feet maximum, except for dwellings and agricultural buildings.(b)Height. Thirty-five feet, except for agricultural buildings, cell towers, antennas, water tanks, or necessary structural elements for an otherwise compliant permitted land use.
Lot Coverage Limits
In the R-1 Single-Family Residential district of Mason County's Allyn urban growth area, Mason County Code § 17.11.150 caps lot coverage at 40 percent, alongside a maximum density of four dwelling units per gross acre and minimum lot sizes starting at 7,000 net square feet for a single-family home.
Lot Coverage Limit, Allyn UGA, Mason County
Some RestrictionsMason County Code § 17.11.150
The following standards may be altered without a variance only through use of an overlay zone, PD regulations as adopted in Article V of Chapter 17.10 or as a Master Development Plan in conformance with adopted Mason County Regulations. Height and setback standards allow for minor deviations by architectural treatments such as chimneys, copulas, bay windows, porch covers, and door landings. Den...
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