Chino Hills, CA Fence Regulations: Retaining Walls (2026)

On the city's many sloped and hillside lots, retaining walls are regulated by the City of Chino Hills Building Department, and the permit triggers are specific. A building permit is required if any portion of the slope is cut into, no matter how slight; if the wall has more than 3 feet of exposed height; if there is sloping backfill, a surcharge, or any combination of fence and wall height over 6 feet. By contrast, a permit is not required for a level-backfill wall 3 feet or less in exposed height when the distance to the slope or surcharge is greater than the wall height. This city threshold tracks the California Building Code exemption for retaining walls not over 4 feet measured from the bottom of the footing to the top of the wall (unless supporting a surcharge or impounding flammable liquids), but Chino Hills emphasizes the 3-foot exposed-height and slope-cut triggers. Permitted retaining walls require a full submittal: engineered calculations signed by an engineer or architect, a soils report (or lot-specific tract soils parameters), and a wet-stamped plot plan showing property lines, easements, slope heights and gradients, top of wall, top of footing, adjacent grades, drainage, and erosion control. No portion of the wall (including footings, backfill, or drains) may extend beyond the property line, and minimum 90% compaction with a soils-engineer test is required.