Orange County, CA Fence Regulations: Retaining Walls (2026)

The County of Orange Zoning Code Section 7-9-64 applies to any retaining wall in the same way it applies to other walls, in addition to the district's standards. A key measurement rule appears in Section 7-9-24.10(b): the height of a fence that sits on top of a retaining wall is measured from the base of the wall, at the lowest existing grade on the wall, to the highest point of the fence on the highest side of the wall, which limits how high a fence-on-wall combination can rise in a setback. Where the street is higher than the front setback area, Section 7-9-64(b)(7) limits a retaining wall to three and one-half (3.5) feet within the required front setback, with the exposed area of the retaining wall capped at six (6) feet. For structural and permitting purposes, OC Development Services guidance provides that walls that retain level earth more than four (4) feet in height, walls impacted by a surcharge, or walls retaining a slope must be engineered and require building permits. Standard non-retaining garden walls under six feet generally follow the same height limits as fences. Grading associated with a retaining wall may also trigger a Site Development Permit under Section 7-9-66 when large volumes of earth are moved.