Fontana, CA Fence Regulations: Retaining Walls (2026)

Fontana Municipal Code Sec. 2, Building Exemption 4, of the adopted California Building Code (California Code of Regulations Title 24, Part 2, and the International Building Code) to read: retaining walls not over 3 feet in height, measured from the bottom of the footing to the top of the wall, are exempt from the building permit requirement, unless the wall supports a surcharge or impounds flammable or combustible liquids. A surcharge, an added load behind the wall such as a slope, driveway, structure or parked vehicle bearing down on the retained soil, strips the exemption regardless of height, as does any wall holding back flammable or combustible liquid.

Because the measurement runs from the footing bottom, not just the visible face, a wall that looks like it's under 3 feet above grade can still exceed the exempt height once the buried footing is counted, which is why the building official checks footing depth before waiving the permit. This amendment lives in Article III of Chapter 5, the same article that adopts the 2025 California Building Code under Sec. 5-61 and makes violating any of its provisions, including building an unpermitted wall above the exempt height, a misdemeanor under Sec. 5-5.