Redlands, CA Accessory Structures: ADU Rules (2026)

The City of Redlands explicitly states on its Development Services ADU page that 'the City uses current State law for the construction of ADUs.' This matters because Redlands' own ADU regulations in the Municipal Code, codified at sections 18.156.430 through 18.156.460 (from Ordinances 2533 and 2743, adopted 2003 and 2010), still use the obsolete term 'second unit' and were found non-compliant with state law. In a July 14, 2025 Letter of Technical Assistance, the California Department of Housing and Community Development (HCD) asked Redlands to repeal these outdated ordinances. Under the state standards the City applies: detached ADUs may be up to 1,200 sq ft of interior living space; attached ADUs up to 50% of the primary dwelling's floor area (with an 800 sq ft minimum); and junior ADUs (JADUs) up to 500 sq ft. Detached ADU height is generally 16-18 feet (up to 20-25 feet in certain cases). Required setbacks are 4 feet from side and rear property lines. Parking is one space per unit or bedroom, but is exempt within a half-mile of transit or inside historic districts. ADUs in Redlands' Victorian/Craftsman historic districts must use 'the same or a similar design to the principal residence.' All ADUs require a building permit from the Building and Safety Division.