San Benito County, CA Fence Regulations: Retaining Walls (2026)

Retaining walls in unincorporated San Benito County are addressed both by the Zoning Code and by the adopted state building code. County Code Section 25.07.013, Fences, Walls, and Screening, provides that retaining walls more than 48 inches (4 feet) high shall be stepped, a design requirement intended to avoid a single tall, sheer wall face. On the building-permit side, the California Residential Code (Section R105.2), as enforced by the San Benito County Building Division, exempts a retaining wall from a building permit only when it is not over 4 feet in height measured from the bottom of the footing to the top of the wall and does not support a surcharge (such as a slope or structure above) or impound flammable liquids; taller or loaded walls require an engineered permit. A combined retaining-and-fence structure is measured and reviewed under both the zoning height rules in Section 25.07.013 and the building code. Because hillside parcels are common in the county's rural areas, owners should confirm wall height, footing, and drainage requirements with the Building and Planning Division before construction.