ADU rules in Santa Barbara

Detached ADUs are allowed on any lot in a zone that allows residential use with an existing or proposed home, including mixed-use lots, through a ministerial building permit (SBMC 30.185.040.C.1 inland; 28.86.030 in the coastal zone). The code sorts them into 'standard' ADUs, its local track (one ADU per lot, detached up to 850 to 1,200 sq ft), and 'special' ADUs, its version of the Gov. Code 66323 state-exempt units (one new detached unit of up to 800 sq ft on a single-home lot, combinable with a JADU, or up to two new detached units on a lot with two or more homes) (30.185.040.B, L.2-L.3). In the Foothill and Extreme Foothill High Fire Hazard Areas (the Very High Fire Hazard Severity Zone) only special ADUs are allowed, so a new detached unit there is capped at 800 sq ft (30.185.040.C.3; 28.86.030.C.2), an area limit Gov. Code 66314(a) permits on public-safety grounds. The city's unit counts are narrower than state law: Gov. Code 66323(a) allows a converted ADU, a JADU and an 800 sq ft detached unit in any combination on a single-home lot and up to eight detached ADUs beside an existing multifamily building (never more than its unit count), and the city's June 30, 2026 Council report says these state allowances 'supersede any conflicting local zoning regulations until the City adopts updated ordinances.' The city's ADU page likewise says staff defaults to state law wherever the 2023 ordinances conflict with it.

An ADU may be created inside the existing or proposed home, inside an existing accessory building such as a garage, or as an addition attached to the home or an accessory building (30.185.040.D.2; 28.86.035.B), and one JADU of up to 500 sq ft may be created inside a single-family home or its attached garage on a lot with only one home (30.185.040.C.2, D.3; 28.86.035.C). Conversions are allowed citywide as 'special' ADUs: space inside the home, a garage or other accessory building (with one 150 sq ft first-floor addition limited to entry and exit), and on lots with two or more homes up to two units, or 25 percent of the existing units if greater, carved from non-livable space such as garages, basements, storage rooms and upper-floor commercial space (30.185.040.L.2-L.3). New attached additions are 'standard' ADUs, which are not allowed in the Foothill and Extreme Foothill High Fire Hazard Areas, so homes there can add an attached unit only by converting existing space (30.185.040.C.3; 28.86.030.C.2). Fire Department staff asked on March 19, 2026 to keep that limit for non-exempt ADUs, and the June 30, 2026 Council framework proposes retaining it.

Standard ADUs: a detached unit is capped at 850 sq ft with a studio or one bedroom and 1,000 sq ft with two or more bedrooms on lots up to 14,999 sq ft and at 1,200 sq ft on lots of 15,000 sq ft or more, an attached addition at 50 percent of the existing home's living area, a unit converted entirely within an existing home or accessory building only by the existing footprint, and an 800 sq ft attached or detached standard ADU with 4-foot interior setbacks is always allowed regardless of percentage, lot coverage, FAR, open space or front-setback limits (30.185.040.G.1.d, G.2; 28.86.055.A.4, B). Special ADUs are capped at 800 sq ft when new and detached, conversions are uncapped, and JADUs are limited to 500 sq ft (30.185.040.L.4; 28.86.090.D). A detached ADU may be 18 feet tall plus 2 feet to match the home's roof pitch (one story for special units), a standard detached unit may instead match the home's height and stories within the accessory-building limit of two stories and 30 feet, an attached standard unit may reach 25 feet or the home's height, and in the Foothill and Extreme Foothill areas a special detached unit is limited to 16 feet and one story unless it is within one-half mile walking distance of a major transit stop or high-quality transit corridor (30.185.040.H.7, L.5; 30.140.020.I; 28.86.060.G; 28.86.090.E). Title 30 measures floor area as net area inside the exterior walls (30.15.070), and inland a detached standard ADU also counts toward the per-lot cap on accessory-building floor area on single-home lots (1,000 to 1,950 sq ft by lot size; 30.140.020.L via 30.185.040.G.1.b) unless the 800 sq ft guarantee applies, while the coastal text excludes detached ADUs from the aggregate cap for other accessory buildings (28.86.055.C.1). These caps sit within Gov. Code 66314(d)(4)-(5) and 66321(b), but because the city concedes parts of its 2023 ordinances no longer comply with state law, a reading that voids the ordinance under Gov. Code 66316 would substitute the flat 1,200 sq ft state cap for detached units.

No owner-occupancy requirement applies to ADUs. The codified sections still list owner occupancy for any ADU in an RS (inland) or One-Family Residence (coastal) zone submitted on or after January 1, 2025, but only 'unless otherwise prohibited by state law' (30.185.040.E.3.b; 28.86.040.C.2), and Gov. Code 66315 bars an owner-occupant requirement, so the city says owner occupancy 'is not required on any new ADU covenants' and releases owner-occupancy covenants recorded before 2020 on request (30.185.040.E.6). The codes and the city's ADU page still require the owner to live in the home or the JADU on every lot with a JADU (30.185.040.E.3.a; 28.86.040.C.1), but since January 1, 2026 Gov. Code 66333(b) (AB 1154) allows that only where the JADU shares sanitation facilities with the home, and the city applies state law where its ordinances conflict, so a JADU with its own bathroom carries no owner-occupancy requirement. Where owner occupancy does apply, the owner may not rent out both units at once, and hardship waivers of up to three years are available (30.185.040.E.4-E.5).

Inland, no parking is required for an ADU or JADU outside the High Fire Hazard Areas, and a garage, carport or other covered parking converted or demolished for an ADU need not be replaced (30.185.040.J). In any High Fire Hazard Area (the Coastal, Coastal Interior, Foothill and Extreme Foothill areas, which include Campanil, Bel Air, Alta Mesa and, since a 2025 expansion, single-unit parts of the Riviera and San Roque) a non-studio ADU needs one covered or uncovered space, never in tandem, unless it is within one-half mile walking distance of a public transit stop, in one of the historic districts the code names (El Pueblo Viejo, Brinkerhoff Avenue, Riviera Campus, El Encanto Hotel), entirely within existing permitted floor area, where on-street permits are required but not offered, or within 500 feet of a car share vehicle (30.185.040.K.1, K.5). Inside the coastal zone the certified text keeps the home's required parking, so covered spaces displaced by a garage conversion or demolition must be replaced on the lot, and an ADU needs one uncovered space unless it sits on a lot with a single home outside the West Beach, Lower State and East Beach key public access areas and meets one of the same exemptions; JADUs need none (28.86.080.A.1, B-D). Gov. Code 66322(a) bars parking within one-half mile walking distance of transit and in five other cases, including a car share vehicle within one block and an ADU filed with a new home, which the local lists word more narrowly, and 66323(b) allows no unlisted standard on state-exempt units, so the high-fire space conflicts with state law for an 800 sq ft special ADU even though the June 2026 Council report describes 'special parking regulations' for those units. In the coastal zone Gov. Code 66329(a) preserves Coastal Act and LCP requirements, the basis for the coastal parking rules.

ADUs and JADUs are approved ministerially through a building permit within the state time limits, with the city's objective design criteria (roofing, clay tile, skylights, glass guardrails, garage-door infill, grading, height, front-yard placement, matching style, upper-story privacy) checked by staff rather than a design board (30.185.040.H, M.2). Discretionary review by the Single Family Design Board, Architectural Board of Review or Historic Landmarks Commission happens only if the applicant opts out of those criteria or adds exterior work unrelated to the ADU, and modifications or minor zoning exceptions are optional (H.11, M.5); the owner must post a notice sign within five days of applying and record an agreement before the permit issues (M.6, N). Inside the coastal zone (S-D-3 overlay) the city treats ADUs as needing a coastal development permit, which the Staff Hearing Officer decides without a public hearing after 10 days' notice as the city's final action (28.44.110.C, 28.44.120; 28.86.100.A; the codified no-hearing path names a detached ADU beside a single-family home and any ADU on a lot with two or more homes or mixed use, and Gov. Code 66329(a) bars hearings for every ADU coastal permit), while a JADU carved from an existing bedroom without changing the building envelope needs none (28.44.070.D). Gov. Code 66329 requires that coastal decision within 60 days with no hearing and, since AB 462 took effect on October 10, 2025, makes it unappealable to the Coastal Commission under Public Resources Code 30603, so the codified sentence allowing appeals in the appealable area yields.

If rented, the ADU, the JADU and the main home on the lot must be leased for at least 31 consecutive days with no termination before one 31-day occupancy ends, the ADU may not be sold separately from the home, and these terms go into an agreement recorded before the building permit (30.185.040.E.1-E.2, N; 28.86.040.A-B, 28.86.100.H). For an ordinary local-track ADU the 31-day floor is one day stricter than Gov. Code 66315 permits ('rentals of terms 30 days or longer'), while state-exempt units and JADUs must rent for longer than 30 days anyway (66323(e), 66333(g)). The city also classes rentals of 30 days or less as 'Hotels and Similar Uses', not allowed in the RS and R-2 zones, limited by conditional use permit to hotels in historic structures in R-M, and allowed in R-MH (30.295.040.P; Table 30.20.020); per the city's April 2026 STR report, Kracke v. City of Santa Barbara held that the city cannot enforce against STRs in the coastal zone without STR rules approved through Title 28 or the Coastal Land Use Plan, but the ADU rental rule sits in the certified coastal chapter. The Short-Term Rental Program ordinances set for introduction at the October 6, 2026 Council meeting (a new 30.185.395 inland and Chapter 28.91 coastal; outcome not yet published on October 7) would make ADUs, JADUs and the main home on their lot ineligible for STR or homeshare licenses, except a homeshare in a main home occupied by the owner or host. The city has not opted into ADU condominium sales under Gov. Code 66342 (the June 2026 framework proposes it), so separate conveyance exists only through a qualified nonprofit under 66341.