City of San Mateo Law Library
City of San Mateo Municipal Code.

27.70.010 ACCESSORY BUILDINGS.

(a) Location of Detached Accessory Buildings. A detached accessory building located within the rear one-third of a parcel is exempt from the requirements for interior side and rear yards, provided such structure is separated from the principal building by an area not less than four (4) feet in width that is open to the sky.

(b) Maximum coverage of required rear yards. Accessory buildings shall not occupy more than 50% of a required rear yard.

(c) Maximum height of accessory structures in required yards. Accessory structures located in required yards pursuant to subsection (a) shall not exceed the following height limits:

R1 Districts Nine (9) feet to the plate line and sixteen (16) feet to the roof peak.
All other districts Fifteen (15) feet to the plate line.

(d) Habitable floor limitation. In R1 Districts, accessory structures located in required yards pursuant to subsection (a) shall be limited to one habitable floor on the ground level. Habitable floor for the purposes of this subsection shall mean that served by permanent access and containing windows and/or plumbing fixtures, but shall exclude basements.