ADUs San Diego

San Diego aggressively promotes Accessory Dwelling Units (ADUs) to increase housing, allowing at least one detached ADU and one Junior ADU (JADU) on most single-family and multifamily lots, with no maximum size limit for conversions. New 2026 regulations allow ADUs to be sold separately as condominiums, and a "bonus program" permits extra units in exchange for affordability restrictions.Key ADU Regulations in San Diego (2026)Types Allowed: Detached, attached, and Junior ADUs (JADUs, up to 500 sq ft within an existing home).Size Constraints: Generally, up to 1,200 sq ft for detached/attached; however, conversions of existing space are not limited to this maximum.Setbacks: Generally, 4-foot side and rear setbacks, though 0-foot is allowed for certain conversions.Parking: No parking is required for ADUs in most cases, particularly within transit areas.Condo Conversion: New rules allow for the separate sale of ADUs from the primary residence.Financing and DevelopmentSan Diego Housing Commission (SDHC) Loan: Offers an ADU Finance Program with construction-to-permanent loans up to ($250,000) for eligible homeowners.ADU Bonus Program: Incentivizes affordable units by allowing additional market-rate ADUs.Costs: While prices vary, new construction in Southern California generally ranges from ($300-$400) per square foot.Permitting: A building permit is required for all ADUs/JADUs.ResourcesCity of San Diego ADU Website: Provides detailed information, including the Coastal ADU webpage.County of San Diego ADU Handbook: Offers guidance for unincorporated areas.Note: The ADU Fee Waiver Program for the County of San Diego ended on January 9, 2024.