The County of Santa Cruz permits ADUs across most residential zones. County of Santa Cruz follows both state and local ADU laws, allowing most single-family homes to build one detached ADU and one Junior ADU (JADU) per lot. Multi-family properties may be eligible for multiple ADUs, depending on site conditions.

County of Santa Cruz aligns with California’s broader ADU legislation but has its own requirements for height, setbacks, and design review.

• Detached ADU: new independent dwelling unit on the property, or expand an existing detached garage or accessory structure
• Attached ADU: new extension to the existing house or attached garage
• Conversion ADU: Convert part of the existing home, garage or accessory structure
• Junior ADU (JADU): JADUs involve creation of a new living unit, maximum 500 square feet, converted from within the walls of a single-family dwelling, including attached garages and other nonliving spaces

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• Maximum Size:
  
  • Detached: maximum size 1000 sf
  • Attached: 1,000 sf, or 50% of primary dwelling
• Setbacks:
  
  • Minimum 4 ft from side and rear property lines
• Height Limits:
  
  • Detached ADU: maximum height is 16 ft
  • Attached ADUs: maximum height is 28 ft
• Parking Requirements:
  
  • Additional parking is not required if the ADU is:
    
    • The Historic districts
    • Within one block of designated car share parking
    • Within ½ mile walking distance of any transit stop

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To build an ADU in County of Santa Cruz, the following approvals are typically required:

• Zoning compliance review: Confirms the ADU complies with Santa Cruz zoning standards, including lot eligibility, maximum size, building height, and minimum 4-foot side and rear setbacks
• Site plan and elevations: Must show property boundaries, existing structures, proposed ADU placement, access paths, parking layout, and height dimensions
• Architectural drawings: Provide detailed floor plans, roof plans, cross-sections, and exterior elevations to demonstrate compliance with design and building code requirements
• Structural calculations and engineering: Required for any new attached or detached ADU construction to ensure compliance with California Building Code and local seismic standards

Homeowners should also review County of Santa Cruz’s current fee schedule, utility connection requirements, and fire code compliance.

County of Santa Cruz does not have a fixed ADU review timeline; however, state law requires the city to act within 60 days of receiving a complete application. The review period may vary based on the accuracy of submitted materials-missing documents such as structural or energy reports can lead to delays. Using pre-approved ADU plans can help expedite the approval process..

ADUs are allowed on lots with an existing or proposed primary dwelling in any residential zoning district within the County of Santa Cruz. There is no minimum lot size requirement. ADUs must comply with applicable setback, height, and access standards, as well as utility and easement regulations. Properties with unpermitted structures or active code violations are not eligible. Lots located within the Coastal Zone, flood hazard areas, or other environmentally sensitive zones may require additional review or permits.

For the most current and complete information, refer directly to the County of Santa Cruz.

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