Santa Clara County, CA Accessory Structures: Shed Rules (2026)

Section 4.20.020 of the County Zoning Ordinance (Appendix I, Article 4) governs all detached accessory buildings in the unincorporated county. Subsection (B)(3) exempts from chapter regulation any accessory structure whose maximum length plus maximum width plus maximum height does not exceed 16 feet (for example, an 8 by 6 by 2 foot tool shed). Subsection (D) covers urban residential districts (R1, R1E, R2, R1S, RHS, and Al inside urban service areas): height is capped at 12 feet and one story, with a 16-foot ridge allowance for hip or gable roofs measured to the average between ridge and top plate. The shed must sit in the rear half of the lot, within the rear yard, or at least 75 feet from the front property line or edge of ultimate right-of-way. Side and rear setbacks are whatever the California Building Code requires for fire separation rather than a fixed zoning number, and a six-foot separation from the dwelling is required (open-sided trellises excepted). Cumulative rear-yard coverage by detached accessory buildings may not exceed 30 percent. Subsection (E) covers rural districts (A, AR, HS, RR, RS, Al outside urban service areas): the same 12-foot rule applies on lots under 2.5 acres, but lots of 2.5 acres or larger may go up to 35 feet provided side and rear setbacks of at least 30 feet are met for any portion above 12 feet. Plumbing inside any accessory building is limited to two interior fixtures unless a special permit is granted, and no shed may be used for sleeping or dwelling. The County applies these rules only in unincorporated areas; the 15 cities (San Jose, Sunnyvale, Santa Clara, Mountain View, Palo Alto, Cupertino, Milpitas, Campbell, Gilroy, Morgan Hill, Los Altos, Los Altos Hills, Los Gatos, Saratoga, Monte Sereno) set their own codes.