Santa Cruz ADU Standards

Prefab ADU in Santa Cruz

What is an Accessory Dwelling Unit (ADU)?

An ADU is an independent residential unit on the same lot as a primary home, providing additional living space, rental opportunities, or multi-generational housing. A Prefab ADU is a permanent, factory-built backyard home that meets local zoning and building codes, making it ideal for long-term living.

Tiny homes, often confused with prefab ADUs, are small, mobile units built on wheels. While both can be ADUs, prefab ADUs are stationary and built to last, while tiny homes face more zoning challenges due to their mobility.

Planning to Build an ADU in Santa Cruz?

LiveLarge specializes in designing and building ADUs, including prefab ADUs, modular homes, and backyard homes, that meet local standards while optimizing your space. Our experienced team is here to help with permits, design, and construction, ensuring your ADU project is smooth and hassle-free.

Zoning and Lot Size:

ADUs are allowed on any property zoned for residential or mixed-use in Santa Cruz, as long as they are paired with an existing or proposed residential use. You can build a new structure, add an extension to an existing home, or convert a legal structure such as a garage or workshop into an ADU.

There are different categories of ADUs:

  • Statewide Exemption ADUs: ADUs that meet basic standards (e.g., 800 sq. ft. or less for new detached ADUs or conversions within an existing structure) are subject to limited development standards.
  • Non-Exempt ADUs: Larger or more complex ADUs are subject to full compliance with the City’s ADU development standards.

If you have a single-family property or townhome, you may construct one Statewide Exemption ADU, one Non-Exempt ADU, and one Junior ADU, provided they comply with state and local regulations.

For multi-family properties, the number of detached ADUs depends on the number of existing units on the parcel (up to eight detached ADUs). Statewide Exemption conversions are limited to 25% of existing units.

Lot Size and Floor Area:

  • Junior ADU: Max 500 sq. ft.
  • Studio or 1-Bedroom ADU: Max 850 sq. ft.
  • 2+ Bedroom ADU: Max 1,000 sq. ft.
  • Conversion ADUs: No size limitation unless new space is added.

Setbacks and Height:

  • Detached ADUs:
    • One-Story: No setback required.
    • Two-Story: Minimum 4′ setback, max height 16-20 feet.
  • Attached ADUs: Must comply with the setbacks and height of the existing structure, max height 25 feet.

Design and Layout:

  • Kitchen: Must include a full kitchen with a stove, refrigerator, sink, counter space, and cabinets.
  • Bathroom: A full bathroom with sink, toilet, and shower/bathtub.
  • Storage: At least 60 sq. ft. of storage space is required.
  • Entrance: A separate exterior entrance from the main dwelling.

Parking:

  • Outside Coastal Zone: No parking required for ADUs.
  • Inside Coastal Zone: One off-street parking space required, depending on location.

Additional Design Guidelines:

  • Building Separation: Detached ADUs must have a 5-8 foot separation, depending on the location.
  • Architectural Features: Projections (e.g., eaves, bay windows) can extend 2 feet into setbacks, with a 2-foot setback maintained.
  • Roof Decks: Allowed in non-Coastal areas, restricted in Coastal Zone areas.

Rental and Occupancy:

  • Rental Restrictions: ADUs and Junior ADUs cannot be used as short-term rentals.
  • Owner Occupancy: Required for ADUs built before 2020; however, as of 2025, owner occupancy will not be required for ADUs constructed before 2020.

Statewide Exemption ADUs

Statewide Exemption ADUs do not need to meet all local zoning requirements. These include:

  • New Construction Detached ADUs: Up to 800 sq. ft., height limit of 16-20 feet.
  • Conversion ADUs: Can be created in existing non-livable spaces like garages or basements.

For more detailed information, visit the City of Santa Cruz’s official ADU page. Let LiveLarge Home help transform your property with a thoughtfully planned ADU. Whether you’re interested in a prefab ADU, modular home, or tiny home, our expertise in ADU design and construction will ensure your project meets local standards while maximizing space. Contact LiveLarge today to start building your ideal backyard home!

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