Lompoc, CA Accessory Structures: ADU Rules (2026)

Santa Barbara County's ADU and Junior ADU regulations live primarily in Land Use and Development Code (LUDC) Section 35.42.075, with parallel sections in the County's Coastal Zoning Ordinance, the Montecito Land Use and Development Code (MLUDC), and the Toro Canyon Land Use and Development Code. The current standards were adopted by the Board of Supervisors on May 18, 2021 (Ordinance No. 5230 and companion ordinances), with the inland LUDC and MLUDC amendments taking effect on June 17, 2021 - 30 days after adoption - to comply with the 2019 wave of State ADU legislation (Assembly Bills 68, 881, and Senate Bill 13) and subsequent amendments. The County followed up with further amendments in 2023 to address Senate Bill 9 (SB 9) two-unit and lot-split projects and additional State conformance items. (1) ELIGIBILITY. One ADU and one JADU may be established by right on any lot with a proposed or existing single-family dwelling, in compliance with State law. Two ADUs may be allowed on a lot with an existing multifamily dwelling under specified circumstances. (2) SIZE AND SETBACKS. Detached ADUs up to 800 sq ft are allowed by right with minimum 4-foot side and rear interior setbacks, regardless of the underlying zone's larger setback requirement. Larger ADUs are subject to the underlying zone's standard setbacks but cannot be made infeasible by setback rules. Maximum ADU floor area generally caps at 1,200 sq ft for detached units and at 50% of the primary dwelling for attached units. JADUs are limited to 500 sq ft, must be created within the existing or proposed walls of a single-family dwelling, and require owner occupancy of either the JADU or the primary unit. (3) HEIGHT. Detached ADUs are allowed by right up to 16 feet, or up to 18 feet on lots near transit, or up to 25 feet for ADUs above attached garages, consistent with State law. (4) PARKING. State law eliminates ADU parking requirements in most circumstances - on lots within one-half mile of public transit, in historic districts, in permit-parking areas where parking permits are not offered to ADU occupants, on lots where the principal residence is on the historic register, and where covered parking is replaced by the ADU. (5) UTILITIES. ADUs may not be required to have a separate utility connection from the primary dwelling, except for new construction. (6) SHORT-TERM RENTAL PROHIBITION. The County requires a minimum 30-day rental term for permitted ADUs and JADUs, prohibiting their use as vacation or short-term rentals, as authorized by California Government Code Section 66314 (formerly part of Section 65852.2). (7) COASTAL ZONE. Within the coastal zone (Gaviota Coast, Refugio, El Capitan, Hope Ranch coastal areas, Montecito coastal, Summerland coastal, Carpinteria coastal), ADUs are processed under the parallel Coastal Zoning Ordinance and may require a Coastal Development Permit; ESHA, visual-resource, public-access, and other Coastal Act protections apply. (8) FIRE PROTECTION. ADUs in High and Very High Fire Hazard Severity Zones must comply with California Building Code Chapter 7A (wildfire construction) and PRC 4291 (defensible space). (9) IMPACT FEES. ADUs under 750 sq ft are exempt from County impact fees under State law; larger ADUs pay proportional fees.