Castro Valley, CA Privacy & Surveillance: Privacy Screening (2026)

Alameda County zoning regulations for unincorporated areas allow residential fences up to 6 feet in height in rear and side yards without a building permit. Front yard fences are typically limited to 3-4 feet in height depending on the zoning district, to maintain sight lines and neighborhood aesthetics. Fences over the maximum height require a variance from the county. Privacy fences serve an important legal function in California — they help establish a reasonable expectation of privacy, which is relevant for security camera law and recording law purposes. A fenced backyard is generally considered a private area where recording by neighbors would be a violation of privacy laws. Fence materials are generally unrestricted by county code, though some homeowner associations in unincorporated areas may impose additional requirements. The county building code adopts the California Building Code, which requires fences over 6 feet to have engineering and permits. Retaining walls that also function as fences may have separate permit requirements depending on height and soil conditions.