Building an ADU in Santa Barbara

What you can build in Santa Barbara

An ADU is allowed on any legal lot with an existing or proposed home in a zone that allows homes, including mixed-use lots and lots with more units than current zoning allows. It isn't allowed on a vacant lot or a lot with only commercial uses. The inland rules are in Santa Barbara Municipal Code section 30.185.040, last rewritten by Ordinance 6103 in February 2023. The coastal zone rules are in Chapter 28.86.

The city has two kinds of ADUs:

• Standard ADU. One per lot. It can be attached, inside the house or an accessory building, or detached, and it can be larger. Not allowed in the Foothill and Extreme Foothill fire hazard areas (Very High Fire Hazard Severity Zone).
• Special ADU. Smaller units with fixed size, height and setback limits. They allow more than one unit on a lot and are allowed in every fire hazard area. On a single-unit lot you can choose one conversion, one new detached unit, or a junior ADU plus one new or converted Special ADU. On a lot with two or more homes you can convert non-living space (up to two units or 25% of existing units, whichever is more), build up to two new detached units, or do one of each.

State law is broader. The city's ADU project guidance page says new state laws have passed since 2023 (including SB 1211 in 2024 and SB 543 and AB 1154 in 2025), that the ordinance will be updated within the next year, and that where they conflict, "staff defaults to state law." HCD reads state law to require, on a single-family lot, one converted ADU, one junior ADU and one new detached ADU together. On a lot with an existing apartment building, state law allows up to eight detached ADUs (no more than the existing units). See our California page and confirm your options with the Planning Counter. [1][2][3][4]

Size, height and setbacks

Standard ADUs

• Detached: 850 sq ft for a studio or one bedroom and 1,000 sq ft for two or more bedrooms on lots up to 14,999 sq ft; 1,200 sq ft on lots of 15,000 sq ft or more. Floor area ratio and accessory building limits can reduce this. But an 800 sq ft Standard ADU with 4-foot interior setbacks is allowed regardless of limits on floor area ratio, lot coverage, open space, front setback or percent of the house, as long as it meets the other Standard ADU rules.
• Attached: up to 50% of the living area of the existing house.
• Conversions: no size limit, within the existing footprint.
• Height: no higher than the zone allows for accessory buildings, and limited by solar access rules. Within that, the ADU can match the height or stories of the house, or go to 18 feet detached (plus 2 feet to match the roof pitch) or 25 feet attached, whichever is greater. An ADU over a new or rebuilt detached garage can reach the zone's maximum.
• Setbacks: the zone's front setback, 4 feet from interior lot lines, and 5 feet from the main house.
• In a front yard, a new detached ADU must be at least 20 feet back (or the zone's front setback if greater), one story and under 18 feet (plus 2 feet to match the roof pitch) unless it is over a garage, and screened from the street. The city's ADU Guide still says under 17 feet; the 2023 ordinance says 18.

Special ADUs. Under the 2023 ordinance, a new detached Special ADU can be up to 800 sq ft, one story and 18 feet tall (plus 2 feet for a matching roof pitch). In the Foothill and Extreme Foothill fire areas it is limited to 16 feet, unless the lot is within a half mile walk of a major transit stop or high-quality transit corridor. The city's ADU Guide still lists 16 feet for all Special ADUs, so confirm the height with the Planning Counter. Conversions have no size limit.

Design. ADUs that meet the city's administrative design criteria are approved by staff. The criteria cover things like no shiny roofing, garage doors replaced with matching walls, limits on grading, and screening of upper-story decks and windows near neighbors. You can ask a design review body to approve variations instead, but that is a discretionary process you must finish before applying for the building permit. [2][3]

Fire hazard areas and the coastal zone

Fire areas. Only Special ADUs and junior ADUs are allowed in the Foothill and Extreme Foothill High Fire Hazard Areas (the Very High Fire Hazard Severity Zone). ADUs in any High Fire Hazard Area (the Coastal, Coastal Interior, Foothill and Extreme Foothill areas) must meet high-fire construction and defensible space rules, can't use tandem parking, and can't get variances from fire code rules. They also need one parking space unless the ADU is a studio or a parking exception applies (see Parking below). HCD's ADU Handbook says fire hazard maps are "not intended to restrict housing development" and that restrictions based on public safety should be supported with findings.

Coastal Zone. ADUs and junior ADUs are allowed in the city's Coastal Overlay Zone, but every project there gets Planning review for the right level of coastal review. A Coastal Development Permit is required for new detached ADUs on single-family lots, any ADU on a multifamily lot, and other ADUs that may affect coastal resources. If you need one, finish it before applying for the building permit; an exemption or exclusion can be filed with the building permit. The city's ADU Guide says ADU ordinance amendments take effect in the Coastal Zone only once the California Coastal Commission certifies them. The city's guidance page says the Commission found the city's 2020 coastal ADU rules effective in April 2022. Ask the Planning Counter which rules apply to your coastal lot. [2][3][4]

Parking

The 2023 inland ordinance says "no automobile parking spaces are required" for ADUs or junior ADUs. If you convert or tear down a garage or carport to build an ADU, you don't have to replace those spaces. Any optional spaces can be uncovered, tandem (except in fire hazard areas) or in a mechanical lift.

High Fire Hazard Areas. The same ordinance makes an exception there: no parking for a studio, but one covered or uncovered space for any other ADU. No space is needed if the ADU is within a half-mile walk of a public transit stop, in one of the city's architecturally and historically significant historic districts, entirely inside the existing permitted floor area of the house or an accessory building, within 500 feet of a car-share vehicle, or where on-street parking permits are required but not offered to ADU occupants. HCD's handbook says required ADU parking must be allowed in setbacks or as tandem parking unless the city makes specific findings, such as fire and life safety conditions. The city bans tandem spaces in fire hazard areas, so confirm your parking layout with the Planning Counter.

Coastal Zone. The city's ADU Guide says one uncovered space is required for ADUs in the Very High Fire Hazard Severity Zone or the Coastal Zone. It is waived on single-unit lots outside the West Beach, Lower State and East Beach key public access areas if the ADU is within a half-mile walk of transit, within 500 feet of a car-share vehicle, in a historic district, inside existing permitted floor area, or where on-street permits aren't offered to ADU occupants. The guide also says uncovered spaces you remove must be replaced. State law no longer requires replacing uncovered spaces removed to build an ADU, so confirm with the Planning Counter. [2][3][4]

Fees and costs

Impact fees. State law bars impact fees on an ADU with 750 sq ft or less of interior livable space and requires proportional fees above that. School fees are separate. The city's guide says ADUs under 750 sq ft won't trigger school fees, but HCD's handbook says school districts may charge school fees on ADUs larger than 500 sq ft, so confirm with the city.

Other costs the city lists:

• Soils reports for new structures and additions over 500 sq ft.
• Solar panels on new structures, and a new electrical sub-panel.
• Utility undergrounding (SBMC 22.38) for additions over 500 sq ft and 50% of the existing floor area, or when the ADU's value is over 50% of the depreciated value of the house. If a waiver is approved, the in-lieu fee is 5% of total construction cost.
• Removing an old (pre-2020) owner-occupancy covenant costs a $410 processing fee plus $47 recording.

Using a preapproved plan cuts the plan check fee by 25%. Construction and inspection fees still apply. Fire sprinklers may not be needed in some cases; check with the Fire Department. For typical costs, see our ADU cost guide. [1][3][4][5]

Garage conversions and junior ADUs

Garage conversions. You can convert an existing legal garage or accessory building with no setback, even if it's nonconforming. You can also tear it down and rebuild it in the same place and size, with one 150 sq ft first-floor addition. A nonconforming detached garage can be rebuilt with a conforming ADU above or attached to it. The old garage door opening must be replaced with siding, windows or doors that match the building. The city notes a garage conversion usually costs less, but it must meet current building and energy codes, and the foundation, ceiling joists and fire separation may need upgrades. See our garage conversion guide.

Junior ADUs. A junior ADU is up to 500 sq ft entirely within an existing or proposed single-unit home or its attached garage, on a lot with only one home. It needs its own entrance and at least an efficiency kitchen, and it may share a bathroom with the house.

Owner occupancy for junior ADUs. The city's ordinance and guidance say the owner must live in the house or the junior ADU. Since January 1, 2026, state law requires owner occupancy only when the junior ADU shares a bathroom with the house. The city says staff default to state law where its ordinance conflicts, so confirm with the Planning Counter. See our junior ADU guide. [1][2][3][4]

Renting, owner occupancy and selling

You don't have to live on the property to build an ADU. The city says owner occupancy "is not required on any new ADU covenants." Ordinance 6103 contains a clause that would have brought back owner occupancy for ADUs in RS zones applied for after January 1, 2025, unless state law prohibited it. State law (AB 976) made the ban on ADU owner-occupancy rules permanent. If your property has an owner-occupancy covenant recorded before January 1, 2020, you can ask the city to remove it (junior ADU covenants excepted).

If you rent out the house, ADU or junior ADU, each rental must be for at least 31 consecutive days, so short-term vacation rentals aren't allowed. An ADU or junior ADU can't be sold separately from the main home. [1][2][3][4]

How long it takes and preapproved plans

Under state law, the city must tell you within 15 business days whether your application is complete and approve or deny a complete application within 60 days. A detached ADU using a preapproved plan must be decided within 30 days.

Preapproved ADU Program. The city's Preapproved ADU Program offers detached ADU plans already vetted by Planning and Building & Safety. Plan check is usually done within 10 business days, about half the normal review time, and the plan check fee is 25% lower. You must contract with the plan's designer, add site-specific plans, and use the plan exactly as approved. As of October 2026 the city lists a 406 sq ft studio with a sleeping loft (BESHDA's Gable 400). Two other designs are shown for reference only; the city says they can't be used for permits because of the 2025 building code updates, and new compliant plans are coming. The listed plans aren't allowed in historic districts, on properties with historic resources, or in front yards. See our prefab ADU guide and ADU permit guide. [4][5]

Permit steps in Santa Barbara

1. Confirm your ADU is allowed

   Contact the Planning Counter at (805) 564-5578 to confirm your zoning, fire hazard area, coastal status and whether a Standard or Special ADU fits. You can also request an optional Preliminary Zoning Plan Check. [3][5]

2. Get coastal or design approvals first, if needed

   If you need a Coastal Development Permit or want discretionary design review, finish that planning approval before applying for the building permit. [3]

3. Prepare the application

   Complete the ADU Supplemental Application with a Building Permit (BLD) application, and attach plan sets, photos, soils reports and any other supplemental forms as PDFs. For a preapproved plan, use the Preapproved ADU Supplemental Application and your designer's plan set. [3][5]

4. Apply online

   Submit through the city's Accela Citizen Access portal, where you also track review, upload corrections and pay fees. Incomplete submittals are rejected. [3][6]

5. Plan check

   If the ADU meets all zoning standards and the administrative design criteria, Building & Safety reviews and approves it without a hearing. [3]

6. Build and pass inspections

   City staff conduct building inspections during construction. [5]

Pre-approved and sample plans

• Preapproved ADU Program

  Detached ADU plans vetted by the city, with plan check generally within 10 business days and a 25% lower plan check fee; you contract with the plan's designer. [5]

Who to call

• City of Santa Barbara Planning Counter

  ADU zoning questions, Standard vs Special ADUs, coastal review; PlanningCounter@SantaBarbaraCA.gov

  (805) 564-5578

  630 Garden Street, Santa Barbara, CA 93101

  [1][3]

• City of Santa Barbara Building & Safety Counter

  Building permits and plan check; CDBuildingCode@SantaBarbaraCA.gov

  (805) 564-5485

  [6]

Questions people ask