Current regulations and guidance are given on this page: Santa Cruz County Accessory Dwelling Units

The County has recently updated regulations for ADUs and is awaiting certification of these amendments by the California Coastal Commission. Until the Commission acts, certain standards for development are different inside and outside the Coastal Zone. Please be sure to reference the correct brochures for your property.


  1. The parcel must be owner-occupied as evidenced by the filing of a home owner’s property tax exemption, or other appropriate documentation. *
  2. The parcel must be zoned Residential or have a General Plan designation of Residential. Outside of the Coastal Zone, parcels may also be zoned for Agriculture.
  3. The parcel may have no more than one existing single family dwelling. An ADU can also be constructed concurrently with one single family dwelling.  more…….

Outside the Coastal Zone: See Brochure

The following development standards apply to all ADUs:

  1. The ADU may be attached or detached from the main unit. Within the Urban Services Line, the ADU must be located within 100 feet of the main dwelling, and cannot be accessed by a separate driveway or right-of-way unless a variance is issued.
  2. The total Gross Floor Area of the ADU may not exceed 640 sf within the Urban Services Line, or 10% of the parcel size for parcels less than 5000 sf. Outside of the Urban Services Line, on parcels less than 10,000 sf, ADUs may be up to 640 sf, between 10,000sf and 1 acre, ADUs may be up to 800 sf, and on parcels 1 acre or larger, the unit may be up to 1,200 square feet.
  3. One additional parking space is required for each bedroom in the ADU, unless the unit qualifies for an exception. In addition, the primary dwelling must also meet current parking requirements, which are based on the number of bedrooms.   Exceptions from the parking standard are available if the ADU is being created as a conversion of an existing structure, or if it falls within the mapped half-mile buffer of the County’s primary transit routes, see SCCC 13.10.681(F)(2). When the ADU qualifies for an exception, the primary dwelling may maintain any existing parking configuration.
  4. Only one ADU may be constructed per parcel. A parcel may have EITHER a habitable accessory structure with a bathroom OR an ADU, but not both.
  5. The ADU should be architecturally compatible with the main unit in terms of design, color and materials. Doors, windows, balconies, etc., should be situated to preserve the privacy of neighbors. Units inside the Urban Services Line shall not exceed 17 feet in maximum height and 14 feet in average height unless they are constructed above a garage, in which case they may be up to 22 feet in maximum height and 19 feet in average height.
  6. All development standards (i.e., setbacks, lot coverage) for the applicable zone district must be satisfied.  Exceptions to site standards: ADUs built above garages may be built with 5 foot side and rear setbacks in all residential zone districts. Conversion ADUs may utilize any existing legal structure on the property, regardless of compliance with other site standards, provided they conform to the appropriate size limit based on parcel size, and be updated to comply with current Building and Fire Codes.
  7. To file a building application for an ADU, a “Clearance to Apply for Building Permit” form from Environmental Health Services will be required if a septic system is to be used. Fire, Sanitation and Water Districts’ approval requirements must be satisfied during the Building Permit process.
  8. Fire Sprinklers are required only where they are already present in or required for the primary dwelling. Fire Agencies may require alternative methods for complying with the fire code.
  9. ADUs that are created by converting any existing habitable or non-habitable area are not required to provide additional parking, and may also be exempted from some fees. Up to 65% of structural components may be replaced in the course of the conversion, but no additional space may be added or enclosed.   more…….


Outside the Coastal Zone:

Inside the Coastal Zone: