Alameda, CA Fence Regulations: Retaining Walls (2026)

The City of Alameda does not have a stand-alone retaining-wall height limit in its fence ordinance; AMC Section 30-5.14 (Barriers and Fences) regulates fences, walls, and hedges generally but contains no specific retaining-wall provision. Where a wall both retains earth and serves as a barrier, its above-grade portion counts toward the applicable barrier height limit (3 feet in front yards, 6 feet in side/rear yards on residential lots), measured from grade per AMC 30-5.14.c. Retaining walls are reviewed primarily as structures: structural retaining walls require a building permit and engineering, and exterior site work that requires a permit also triggers Planning Design Review under AMC 30-37. Under the California Building Code (adopted by the city), a building permit is generally required for retaining walls more than 4 feet in height measured from the bottom of the footing to the top of the wall, or any wall retaining a surcharge or supporting a slope. Because the city has no published numeric retaining-wall standard of its own, applicants should confirm specific height, setback, and engineering requirements with the Alameda Permit Center before construction, especially on sloped or waterfront lots and within historic districts where Design Review applies.