Mason County, WA Home Business: Signage Rules (2026)

Section 17.03.021(5) of the Mason County Code is the sign standard inside the broader cottage industry rule that lets a home-based business operate in unincorporated Mason County, WA without a special use permit. The provision allows exactly one sign, capped at twelve square feet, and otherwise prohibits any alteration to the outside appearance of the dwelling or premises, or other visible evidence of the business, that is not consistent with the property's residential character. That single-sign limit sits alongside six other standards in the same section covering parking, screened outdoor storage, owner residency, employee counts, off-property noise and odors, and a five percent cap on added local traffic; a cottage industry must meet all seven at once to keep its by-right status.

A larger sign, a second sign, or other visible commercial signage counts as an exterior alteration inconsistent with residential use, which removes the standards-compliant exemption and forces the operator into the special use permit process administered by Mason County Community Development and decided by the county hearing examiner under MCC 2.128. The rule applies countywide in the unincorporated area, including the Belfair, Allyn and Shelton urban growth areas, and dates to the 2005 development code, Ordinance 108-05, as amended through Ordinance No. 2023-045.