Concord, CA Fence Regulations: Retaining Walls (2026)

Concord regulates retaining walls under the California Building Code as adopted through Municipal Code Title 15 (Buildings and Construction) and Title 18 zoning standards. Per CBC §105.2, retaining walls that are not over 4 feet in height measured from the bottom of the footing to the top of the wall are exempt from a building permit unless supporting a surcharge (driveway, structure, sloping fill) or impounding Class I, II, or IIIA liquids. Walls over 4 feet, or any wall with a surcharge, require engineered plans stamped by a licensed civil engineer and a building permit. Permit review includes structural analysis, drainage design, and grading compliance. Hillside development standards apply in Concord's sloped neighborhoods (Clayton Valley, Ygnacio Valley foothills) where cumulative wall heights may be regulated. Fences on top of retaining walls count toward the combined height limit from finished grade on the low side. Setbacks from property lines typically match fence standards. Walls disturbing soil may require a grading permit and NPDES construction stormwater compliance. Dilapidated, bulging, or failing walls are treated as public nuisances.