Rocklin, CA Fence Regulations: Retaining Walls (2026)

Under California Building Code Section 105.2, Item 4 (adopted by Rocklin via RMC Title 15 Buildings and Construction), a building permit is required for retaining walls that are more than 4 feet in height measured from the bottom of the footing to the top of the wall, or any retaining wall that supports a surcharge such as a driveway, parking area, or structure, or impounds Class I, II, or III-A liquids. Walls 4 feet or less without a surcharge are exempt from a building permit but must still meet engineering, setback, and drainage standards. For zoning purposes under RMC Ch. 17.76, the combined height of a retaining wall and a fence on top of it is generally counted toward the 6-foot side/rear or 30-inch front-yard limits when both are within the same yard area, unless the retaining wall is supporting actual grade change (in which case the fence height is measured from the higher finished grade). Drainage from retaining walls must not be directed onto neighboring property in a way that creates nuisance under RMC Title 8 (Health and Safety).