Mendocino County, CA Accessory Structures: Shed & Carport Rules (2026)

Sec. 015(F) of the Mendocino County Code sets the dimensional cutoff for the reduced accessory-structure setback: a detached garage, detached storage shed, or similar detached accessory building not exceeding 15 feet in height at the ridge and 500 square feet of floor area may sit as close as four feet to a rear property line that does not have street frontage. That four-foot allowance only applies to the rear line; where the property line in question has street frontage, the shed has to meet the standard front, side, or corner setback that applies to the zoning district instead, per the same subsection.

A shed that exceeds either the 15-foot ridge height or the 500-square-foot floor area drops out of this reduced-setback category entirely and is treated as a standard accessory building subject to the district's normal yard setbacks measured from all property lines. 152, Property Development Standards, alongside the county's general yard and setback exceptions for eaves, decks, and swimming pools, all adopted under Ordinance No. 4538 in the September 10, 2024 zoning code rewrite. Because the standard is measured to the ridge, not the eave or plate line, a shed with a steep roof pitch can trip the 15-foot limit even if its walls are shorter.

Owners planning a shed near the size ceiling should confirm floor area calculations include any loft or partial second level, since the code measures gross floor area for similar structures elsewhere in the same chapter.