Accessory dwelling units (ADUs) are allowed on any parcel where the zoning district or General Plan allows residential uses, and there is an existing or proposed primary dwelling. ADUs can be attached or detached from the primary dwelling, new construction or converted from existing space, and can be standard or junior ADUs. For more information see Types of ADUs.
State Laws in Effect
On January 1, 2020, new state ADU laws went into effect that required updates to the County’s ADU ordinance. These laws include AB 68, AB 587, AB 881 and SB 13. Key provisions contained in these laws cover the topics of streamlined ADU review, reduced fees, more lenient development standards, lower parking requirements, Junior ADUs (JADUs), multifamily dwelling ADUs, owner occupancy requirements, short-term rentals, nonconformities, code enforcement, and separate sale of ADUs. In January 2020 and again in March 2022, the local Santa Cruz County Code was updated in alignment with state law requirements.
Structure Legality. Only structures constructed legally may be converted to ADUs. Illegal structures may also be converted to ADUs but will be treated as new construction projects with associated requirements. Property owners seeking to legalize ADUs in illegal structures that cannot meet current building code may pursue the County’s Safe Structures Program
Septic Requirements. Parcels on septic may require septic system upgrades and should contact the Environmental Health Department for more information.
Short-Term Rentals. Short-term rentals (rentals less than 30 days) are not allowed on parcels with ADUs. Properties with ADUs are therefore not allowed to participate in the County’s Vacation Rental or Hosted Rental programs.
Most ADUs require only a building permit, using the County’s online ePlan review process. ADU building permit applications are reviewed within 60 days of submittal.
Additional review may be required before a building permit may be issued for certain changes to non-conforming dwellings, or for ADUs located in the coastal zone.
Number of ADUs Allowed
Parcels with single-family dwellings: one ADU and one JADU are allowed per single-family dwelling. Note that if both an ADU and JADU are proposed to be attached to a single-family dwelling, multifamily building code requirements may apply. Learn more about this rule here.
Parcels with multifamily dwellings: two detached ADUs are allowed which may be attached to each other, and up to 25% of units can have an ADU converted from existing non-livable space such as a garage or storage area.
Parcels with non-conforming density: on parcels where the number of existing dwelling units exceeds the density allowed on the parcel by the General Plan, one or more of the dwelling units is considered “non-conforming” and the number of ADUs allowed depends on the specific non-conforming situation.
JADU: Minimum 150 sf, maximum 500 sf
Conversion ADUs: Minimum 150 sf, no maximum size
New Construction ADU: Minimum 150 sf, maximum based on parcel size (see Types of ADUs).
Enter your address or parcel number here and find out the maximum allowable ADU size for your parcel.
Parking is not required for Conversion ADUs or JADUs. Property owners converting garages to ADUs do not need to replace lost parking spaces except in certain coastal areas.
New Construction ADUs require one new parking space, except in the following locations when outside certain coastal areas:
- Historic districts
- Within one block of designated car share parking
- Within ½ mile walking distance of any transit stop (except in designated coastal areas )
Coastal Parking Regulations:
- Within the Live Oak Designated Area (LODA), Seacliff/Aptos/La Selva Designated Area (SALSDA), Davenport/Swanton Designated Area (DASDA), and Opal Cliff Drive between 41st Ave and the City of Capitola, one parking space is required for new construction ADUs, with no exceptions, and replacement parking is required when existing parking is demolished or converted for construction of an ADU.
New Construction ADUs have special setbacks and height standards that define the building envelope for these structures.
- Minimum Setbacks from Property Line
- Minimum front setbacks: standard for the zone district
- Minimum side setbacks: 4 feet
- Minimum rear setbacks: 4 feet for building height up to 16 feet, 8 feet for building height over 16 feet
- Minimum separation between ADU and other structures: 3 feet (or more if needed for fire separation per the California Residential Code). Learn more here.
- Maximum Height
- Attached ADUs: standard for the zone district (usually 28 feet)
- Detached ADUs outside the Urban Services Line: standard for the zone district (usually 28 feet)
- Detached ADUs inside the Urban Services Line: 16 feet (21 feet allowed with Zoning Administrator approval)
- ADUs above Detached Garages inside the Urban Services Line: 24 feet at roof peak, 20 feet at top of exterior wall
- Maximum Floor Area Ratio and Lot Coverage. ADUs are subject to standard FAR and lot coverage, except that an ADU up to 800 sf is allowed, regardless of FAR and lot coverage.
- Coastal Special Communities
- Pleasure Point: Maximum height for ADUs above Detached Garages: Maximum 22 feet at roof peak, 18 feet at top of exterior wall, and meet standards of the PP combining zone district
- Seascape Beach Estates: ADUs follow setbacks, height, FAR and lot coverage standards for the SBE combining zone district
Permitting, planning and other fees vary with ADU type and parcel location. To the extent fees are based on size of the unit, number of bedrooms or project valuation, ADU design can influence fee costs. See the Financing Guide and the Fee, Cost and Cash Flow Estimator for more information. Certain fees are waived or reduced for ADUs as follows:
- Reduced building permit fees for Conversion ADUs.
- Waiver of sewer and water connection fees for JADUs and Conversion ADUs.
- Waiver of Planning Department permit fees for ADUs ≤ 640 sf.
- Waiver of impact fees for ADUs less than 750 sf. Impact fees for larger ADUs are proportional to square footage.
- Waiver of transportation and roads fees when no parking is required for ADU.
- Waiver of Affordable Housing Impact fee for Conversion ADUs.
Alternatives to ADUs
Dwelling units may include up to one "efficiency kitchen” in addition to one standard kitchen. Adding an efficiency kitchen to an existing bedroom, den, or family room can create a separate living space for a family member or a renter, if interior access to the rest of the house is maintained. In some cases, an efficiency kitchen may be an appropriate alternative to a JADU. See the Types of ADUs page to learn more about the “Efficiency Kitchen Alternative.”