Side by side · California
Compare ADU rules across California
Flexible on where you build? The same backyard cottage can be routine in one city and impossible in the next. This table puts 120 California cities side by side so you can shortlist the friendly ones before reading a single ordinance, or narrow it to just the cities you are deciding between. Every value is summarized from the city's own code; open a city's page for the full notes, citations, and fine print.
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| City | Detached ADU | Attached / internal | Max size | Owner occupancy | Extra parking | Approval |
|---|---|---|---|---|---|---|
| Alameda | Allowed | Allowed | 1,200 sq ft (attached or detached), 800 sq ft always allowed; conversions uncapped under state law; JADU 500 sq ft; detached 18 ft, 20 ft with matching roof pitch; pending ordinance (effective about 11-5-2026) measures interior livable space and caps attached additions at 50% of the home (850/1,000 sq ft state floor) | Not required | None: no off-street parking minimum for any use citywide, and no replacement parking for a converted or demolished garage (one space per ADU is the maximum allowed) | Permitted use |
| Alameda County | Allowed | Allowed | 850 sq ft detached with 0-1 bedroom, 1,200 sq ft with 2+ bedrooms (interior livable space); attached 50% of the existing home up to 850 sq ft (0-1 bedroom) or 1,000 sq ft (2+), 850 sq ft always allowed; conversions uncapped; JADU 500 sq ft; A district lone ADU up to 1,200 sq ft; 16 ft detached (18-20 ft near major transit), 25 ft attached, 2 stories max | Not required | 1 on-site space per ADU unless exempt (1/2-mile walk to public transit, historic property or district, within the home or an accessory structure, permit-parking area, car share within 1 block, no bedroom, filed with a new home); none for state-exempt (Gov. Code 66323) units or JADUs; no replacement parking | Permitted use |
| Anaheim | Allowed | Allowed | Detached: 1,200 sq ft. Attached: 50% of the main dwelling or 1,200 sq ft, whichever is less, but studio and one-bedroom units are permitted up to 850 sq ft and units with two or more bedrooms up to 1,000 sq ft regardless. Any ADU up to 800 sq ft is allowed. JADU: 500 sq ft. Minimum unit size 150 sq ft. | Not required | Studio ADU: 0 spaces. ADU with 1+ bedrooms: 1 space, waived within a half-mile walk of transit, in a historic district, for units within the existing or proposed home or an existing accessory structure, where on-street permits are not offered to ADU occupants, within one block of a car-share station, when a garage or carport is demolished or converted for the ADU, or when the ADU is built with a new home. JADU: 0 spaces. No replacement parking when a garage, carport or covered parking is demolished or converted for an ADU or JADU. | Permitted use |
| Bakersfield | Allowed | Allowed | 1,200 sq ft detached; attached up to 50% of the existing home but at least 800 sq ft; 800 sq ft state-exempt detached unit; conversions of existing space not size-capped; JADU 500 sq ft | Not required | None: no minimum for ADUs (BMC 17.58.110) or for single-family homes; garage or carport spaces lost to an ADU need no replacement | Permitted use |
| Berkeley | Allowed | Allowed | 1,200 sq ft outside the Hillside Overlay; inside it 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms). Same caps for attached and detached, no percent-of-home cap, measured as gross floor area to the outside walls. JADU 500 sq ft. Height: 25 ft for new construction outside the hills; in the Hillside Overlay 20 ft detached and, attached, 25 ft or the existing building's limit, whichever is lower. | Not required | None. No off-street parking is required for any ADU or JADU, in any district. | Permitted use |
| Burbank | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms), attached or detached (the code measures to exterior walls; state law now uses interior livable space); 800 sq ft in the Mountain Fire Zone and for front-yard ADUs; state-exempt detached unit 800 sq ft; conversions up to the existing structure plus 150 sq ft for access; JADU 500 sq ft; detached 17 ft (18 ft plus 2 ft near major transit), 23 ft over a garage | Not required | 1 space per ADU (or per bedroom if fewer) unless exempt: within 1/2 mile walk of public transit, historic district, inside the house or an existing accessory structure, permit-parking street, car share within one block, or no feasible on-site location; none for JADUs or state-exempt units; converted or demolished garages need no replacement | Permitted use |
| Burlingame | Allowed | Allowed | 1,000 sq ft of interior livable space for a local-track attached or detached ADU; 800 sq ft for the state-exempt detached ADU; conversions uncapped; JADU 500 sq ft; height 16 ft detached (18 ft near major transit or beside a multistory multi-unit building, +2 ft for a matching roof pitch), attached 30 ft (25 ft in the Hillside Overlay) or the district limit, two stories | Not required | 1 space for a new local-track ADU unless exempt; none within 1/2 mile of public transit (any bus stop or train station), for conversions, state-exempt units or JADUs; no replacement parking | Permitted use |
| Carlsbad | Allowed | Allowed | Detached 1,200 sq ft (800 sq ft for the state-exempt unit); attached new construction 50% of the home or 1,200 sq ft, whichever is less, but at least 800 sq ft; conversions within existing space (plus 150 sq ft for access); JADU 500 sq ft; detached 16 ft (18 to 20 ft near the Coaster stations), attached 25 ft | Not required | 1 space per ADU unless exempt (within one-half mile walking distance of transit, conversions, historic district, car share, permit parking); none for JADUs or state-exempt units; lost spaces replaced only in the coastal Parking Replacement Areas | Permitted use |
| Carson | Allowed | Allowed | Detached 1,200 sq ft; attached 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms), or 50% of the home if smaller, never below 800 sq ft; conversions uncapped; JADU 500 sq ft | Not required | Up to 1 space per ADU; none for JADUs, conversions, or ADUs within a half-mile walk of public transit | Permitted use |
| Chino | Allowed | Allowed | Detached 1,600 sq ft in RD1/RD2, 1,200 sq ft elsewhere; attached 50% of the home up to 1,600/1,200 sq ft (never below 800); 800 sq ft state-exempt detached unit; JADU 500 sq ft; detached 16 ft one story (18 ft near transit), attached 25 ft two stories | Not required | 1 space per ADU at most (local text says 1 per bedroom); none for studios, JADUs, conversions, state-exempt units, or within 1/2 mile of transit | Permitted use |
| Chula Vista | Allowed | Allowed | Detached ADU: 1,200 sq ft. Attached ADU: 50 percent of the existing home or 800 sq ft, whichever is greater (the city's table applies the same figure to converted ADUs). JADU: 500 sq ft of interior livable space. No minimum size may bar an efficiency unit; the city's table sets no size maximum for detached ADUs on multifamily lots. | Not required | None per the city's published ADU standards ('No parking requirements' for single-family lots, 'No parking required' for multifamily lots). State law in any case caps ADU parking at one space per unit or per bedroom, whichever is less, allows tandem parking on a driveway, bars replacement parking when a garage or carport is demolished or converted for an ADU, and bars any parking requirement for conversion ADUs, ADUs within a half mile walking distance of public transit, and the other Gov. Code 66322 cases. | Permitted use |
| Concord | Allowed | Allowed | 1,000 sq ft of living area on lots under 12,000 sq ft net, 1,200 sq ft on larger lots, and no more than 50% of the main home (800 sq ft always allowed); state-exempt detached unit 800 sq ft; JADU 500 sq ft; 16 ft detached (18 to 20 ft near major transit), 25 ft attached | Not required | 1 space per ADU or per bedroom, whichever is less, unless exempt (1/2 mile walk to transit, conversions, historic districts, car share, state-exempt units, ADU filed with a new home); none for JADUs or for lost garage spaces | Permitted use |
| Corona | Allowed | Allowed | 1,200 sq ft detached; attached 50% of the primary dwelling (never below 800 sq ft); conversions of existing space uncapped; state-exempt detached unit 800 sq ft; JADU 500 sq ft; height per zone (2 stories/30 ft in R-1-7.2) | Not required | 1 space per ADU or per bedroom (whichever is less) for new attached or detached units; none within 1/2 mile walk of transit, in historic districts, for conversions, JADUs or state-exempt (Gov. Code 66323) units; converted garages need no replacement | Permitted use |
| Coronado | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) for new attached or detached ADUs; 800 sq ft with 4-ft side/rear setbacks always allowed; conversions uncapped; JADU 500 sq ft; carriage-house ADU 400 sq ft upstairs; ADU area counts toward the lot's FAR when built with a new home; detached 16 ft (18 ft near major transit, plus 2 ft for a matching roof pitch) | Not required | 1 space per ADU (tandem, uncovered or in side/rear setbacks allowed; none for JADUs or ADUs deed-restricted as affordable), plus replacement of any garage or required parking an ADU or JADU displaces; the city grounds both in its certified Local Coastal Program and the local text omits the state transit and conversion waivers | Permitted use |
| Costa Mesa | Allowed | Allowed | 1,200 sq ft detached; attached the greater of 50% of the home or 1,000 sq ft; multifamily lots 850 sq ft detached (1,000 with 2+ bedrooms); conversions uncapped; JADU 500 sq ft; 150 sq ft minimum; 27 ft or two stories max | Not required | None (parking optional for ADUs and JADUs) | Permitted use |
| Daly City | Allowed | Allowed | Detached 1,200 sq ft; attached 50% of the home or 850 sq ft (1,000 sq ft with 2+ bedrooms), whichever is greater; conversions uncapped; 800 sq ft state-exempt detached; JADU 500 sq ft; height 18 ft detached (20 ft with matching roof pitch), 25 ft and 2 stories attached | Not required | None (since 2020 the city treats every residential lot as within 1/2 mile of public transit); no replacement parking for converted or demolished garages; none for JADUs | Permitted use |
| Dana Point | Outside the coastal zone (about 52 percent of the city's 4,134 acres), Ord. 26-07 makes detached ADUs a ministerial use from about 10-15-2026: a state-exempt detached unit of up to 800 sq ft of livable space with 4 ft side and rear setbacks on any lot with an existing or proposed single-family home (§ 9.07.212(E)(2)), up to eight detached units on a lot with an existing multifamily building and two with a proposed one (E)(4), and a local-track detached unit under § 9.07.212(F) (one per single-family lot; none in multifamily or mixed-use zones unless the lot holds a single-family home). In six mapped Public Safety Areas, a local-track ADU on a lot whose existing development is nonconforming as to parking or driveway length needs a discretionary Site Development Permit ((F)(1)(c)). Inside the coastal zone (the Coastal Overlay District, about 48 percent of the city), Ord. 26-07 has no effect until the Coastal Commission certifies an LCP amendment (Ord. 26-07 § 6), and the city applies the certified LCP rule that Ord. 26-08 reinstated as § 9.07.210: a detached second unit of up to 1,200 sq ft needs a Planning Commission Conditional Use Permit plus a coastal development permit. Gov. Code 66317(a)(1) requires ministerial approval without a hearing, but 66329(a) preserves the Coastal Act, and HCD's 8-13-2025 notice accepted that a fully certified LCP's conflicting provisions supersede State ADU Law inside the coastal zone. DPZC § 9.07.212(E)(2), (E)(4), (F)(1)(b)-(c), (F)(3) and Ord. No. 26-07 § 6 (adopted 9-15-2026, effective about 10-15-2026); DPZC § 9.07.210(b) as reinstated by Ord. No. 26-08 (adopted 9-15-2026; certified LCP text); Gov. Code 66317(a)(1), 66323(a)(2), (a)(4), 66329(a)Full rules for Dana Point Ordinance read October 2026 | Outside the coastal zone, Ord. 26-07 allows ministerially one ADU and one JADU within the existing or proposed space of a single-family home (an ADU may instead occupy an existing accessory structure, with up to 150 sq ft of expansion for access), multifamily conversion ADUs (the greater of 25 percent of the existing units or one per building), and a local-track attached ADU of new construction (§ 9.07.212(E)(1), (E)(3), (F)). An attached ADU may be two stories up to 25 ft or the zone height, whichever is lower ((F)(5)(c)). The § 9.09.020 use tables list JADUs as P* in the RSF districts, RBR 12 and RSF 22 but X in the RBRD 18, RD 14 and RMF districts, narrower than Gov. Code 66323(a)(1) for single-family lots in those zones. Inside the coastal zone an attached second unit, like a detached one, needs a Planning Commission Conditional Use Permit and a coastal development permit under the certified LCP text (§ 9.07.210(b) as reinstated by Ord. 26-08), and the LCP says nothing about JADUs or conversions, so how the city handles them there is undocumented. DPZC § 9.07.212(E)(1), (E)(3), (F)(5)(c) and § 9.07.215 (Ord. No. 26-07); DPZC § 9.09.020(b) use tables; DPZC § 9.07.210(b)(1) (Ord. No. 26-08); Gov. Code 66323(a)(1), (a)(3), 66329(a), 66333Full rules for Dana Point Ordinance read October 2026 | Outside coastal zone: 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space; attached also max 50% of the home but never below 800 sq ft; 800 sq ft state-exempt detached; conversions uncapped; JADU 500 sq ft; 16 ft detached (18 to 20 ft in some cases), 25 ft attached. Coastal zone (certified LCP): attached 30% of the home's living area, detached 1,200 sq ft | Not required | Outside coastal zone: 1 space per ADU (none for studio/efficiency units) unless within 1/2 mile walking distance of public transit including bus stops, a conversion, in a historic district or permit-parking area, near car share, or built with a new home; none for state-exempt units or JADUs. Coastal zone (certified LCP): 1 additional stall per second unit | Outside the coastal zone an ADU or JADU needs an ADU (or JADU) Permit plus a building permit, which the Community Development Director decides "ministerially without any discretionary review or a public hearing" within 60 days of a complete application (§ 9.07.212(D)(4)(a)-(b); § 9.07.215(C)(4)); the city's ADU page lists a $5,422 ADU Permit fee. Two discretionary Site Development Permit paths heard by the Planning Commission remain: local-track units on lots in the six Public Safety Areas whose existing development is nonconforming as to parking or driveway length ((F)(1)(c)-(d)), and any unit that exceeds the objective standards ((H)); HCD's 6-8-2026 preliminary review called the PSA rule a moratorium that needs HCD approval under Gov. Code 66300(b)(1)(B)(ii) before it can take effect. Inside the coastal zone a second unit needs a Conditional Use Permit approved by the Planning Commission (§ 9.07.210(b), certified LCP) plus a coastal development permit; Gov. Code 66329(a), as amended by AB 462 effective 10-10-2025, requires the city to approve or deny the coastal permit within 60 days under 66317, concurrently with the ADU review and without any required hearing, and 66329(c) bars appeal of that decision to the Coastal Commission. The value is "varies" because the same ADU is ministerial inland and a conditional use in the coastal zone. DPZC § 9.07.212(D)(4), (F)(1)(c)-(d), (G), (H) and § 9.07.215(C)(4) (Ord. No. 26-07); DPZC § 9.07.210(b) (Ord. No. 26-08); HCD preliminary review of 6-8-2026 (Supporting Document B to the 9-1-2026 council agenda report, item 9); Gov. Code 66300(b)(1)(B), 66317(a), 66329(a), (c)Full rules for Dana Point Ordinance read October 2026 |
| Downey | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms), detached or attached; attached also capped at the greater of 800 sq ft or 50% of the existing home; conversions uncapped; JADU 500 sq ft; detached 16 ft tall (18 ft plus 2 ft roof pitch near major transit), attached 25 ft, two stories max | Not required | 1 uncovered space per new ADU (existing driveway or tandem OK) unless exempt: within 1/2 mile walk of public transit, inside the home or an accessory structure, historic district, car share within a block, permit-parking area, or filed with a new home that qualifies; none for JADUs | Permitted use |
| El Cajon | Allowed | Allowed | 1,200 sq ft (attached or detached, habitable space), never larger than the main home incl. attached garage; 800 sq ft state-exempt detached unit always allowed; JADU 500 sq ft; 16 ft at 4 ft setbacks (18 ft near major transit or beside a 2-story home) | Not required | 1 space per ADU unless exempt (within 1/2 mile of public transit, conversions, JADUs, ADUs permitted with a new home); state law bars it for 66323 state-exempt units | Permitted use |
| El Cerrito | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); attached the greater of 50% of the home or 800 sq ft, within those caps; conversions uncapped; JADU 500 sq ft | Not required | None | Permitted use |
| El Monte | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) for a new detached or attached ADU; attached also capped at 50% of the home (state law guarantees at least 800 sq ft); 800 sq ft state-exempt detached unit; conversions of existing accessory structures uncapped; JADU 500 sq ft; detached 16 ft (18 ft near major transit), attached 25 ft in R-1C and 30 ft (2 stories) elsewhere | Not required | 1 space per ADU or per bedroom, whichever is less (uncovered and tandem on the driveway allowed); none within 1/2 mile walking distance of public transit, for ADUs inside the home or an accessory building, for state-exempt units or JADUs; no garage replacement | Permitted use |
| Elk Grove | Allowed | Allowed | 1,200 sq ft detached; attached: the greater of 50% of the existing home or 850 sq ft (studio/1 bedroom) / 1,000 sq ft (2+ bedrooms); conversions: existing space plus 150 sq ft for access; JADU 500 sq ft; minimum 150 sq ft. Height: detached 16 ft (18 ft plus 2 ft roof pitch within 1/2 mile of major transit; 18 ft on multistory multifamily lots; 30 ft in AG/AR zones; zone maximum inside the buildable envelope); attached 25 ft or the home's height, whichever is greater | Not required | None in most cases (conversions, ADUs within 1/2 mile walking distance of public transit including any bus stop, state-exempt 66323 units, JADUs, and the other state exemptions); otherwise at most 1 space per ADU (the city text's 1 space per bedroom is capped by state law); no replacement parking for a converted or demolished garage | Permitted use |
| Encinitas | Allowed | Allowed | 1,200 sq ft or the main home's living area, whichever is less (attached or detached), but never below 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); 800 sq ft with 4-ft side/rear setbacks always allowed; JADU 500 sq ft; detached 16 ft at reduced setbacks (18 ft near major transit, 20 ft with matching roof pitch), zone height (22 or 26 ft) at zone setbacks | Not required | 1 space per ADU (tandem or in setbacks allowed) unless within 1/2 mile of public transit (any bus stop or the train station), a conversion of existing space, in a historic district, near car share or where street permits are not offered; none for JADUs, state-exempt units or (under state law) studios; lost parking replaced only west of Coast Highway 101 between Swami's and La Costa Avenue per the city guide | Permitted use |
| Escondido | Allowed | Allowed | 1,200 sq ft of interior livable space for a Standard ADU, attached or detached (no percent-of-home cap); 800 sq ft for the state-exempt detached unit; conversions of existing space uncapped; JADU 500 sq ft; height 24 ft detached, 25 ft attached, or the main home's height if taller | Not required | None | Permitted use |
| Fairfield | Allowed | Allowed | Detached 1,200 sq ft; attached 50% of the main home or 1,200 sq ft, whichever is less (state floors: 850 sq ft, 1,000 sq ft with 2+ bedrooms, 800 sq ft always allowed); conversions of existing space uncapped; JADU 220-500 sq ft; 16 ft tall (state floors: 25 ft attached, 18 ft detached near transit) | Not required | None for ADUs or JADUs (citywide, any lot); converted garage spaces need not be replaced | Permitted use |
| Folsom | Allowed | Allowed | 850 sq ft (studio/1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior living space for local-standards ADUs; attached also max 50% of the existing home (800 sq ft floor); 800 sq ft state-exempt detached unit and multifamily detached units; conversions uncapped; JADU 500 sq ft; detached height 25 ft or the home's height, whichever is less | Not required | 1 space for a new local-standards detached ADU (per unit or per bedroom, whichever is less; studios none) unless exempt; none within 1/2 mile walk of public transit, in the Historic District, for attached ADUs, JADUs, conversions or state-exempt units; no replacement parking | Permitted use |
| Fontana | Allowed | Allowed | JADU: 500 sq ft of interior livable space. Class 1 detached (state track): 800 sq ft. Class 2 ADU, attached or detached: 1,200 sq ft, and an attached unit is further capped at 50 percent of the primary dwelling's floor area; no lot-coverage, FAR, setback, or open-space standard may force a Class 2 ADU below 800 sq ft. Conversion ADUs: limited to the existing space plus up to 150 sq ft for ingress and egress | Not required | 1 off-street space per ADU under the Class 2 local standards (tandem or setback-area parking allowed); waived within a half mile walking distance of public transit, in an architecturally and historically significant historic district, for ADUs converted from the primary residence or an accessory structure, when required on-street permits are not offered to the ADU occupant, or with a car-share stop within one block. No replacement spaces required when a garage, carport, or covered space is demolished or converted for the ADU. JADUs and Class 1 state-track ADUs: no parking required | Permitted use |
| Fremont | Allowed | Allowed | 1,200 sq ft detached, 1,000 sq ft attached addition (interior livable space); conversions of existing space uncapped; 16 ft detached height (18 ft near transit) | Not required | None (no replacement parking for converted or demolished spaces) | Permitted use |
| Fresno | Allowed | Allowed | 1,400 sq ft, or 50% of the primary home's floor area if greater (attached or detached); JADU 500 sq ft; height 30 ft or the zone limit if higher, multi-story allowed; side and rear setbacks 4 ft or less | Not required | None | Permitted use |
| Fresno County | In the unincorporated county a detached ADU needs only a ministerial building permit wherever Article 2 lists ADUs as permitted: the AE, AL, A-1 and A-2 agricultural zones, the R-A, R-R, R-1 family, R-2 and R-3 residential zones, and the C-P, C-4 and R-P commercial zones (the C-6 zone needs a conditional use permit). Section 834.4.030.B.3 prohibits ADUs and JADUs in the mapped Low Water Area, generally east of the Friant-Kern Canal or west of Interstate 5, which the county's GIS layer draws over about 3,780 of the county's roughly 6,010 square miles (including national forest and park land) and which takes in the foothill and mountain communities such as Auberry, Prather, Tollhouse, Shaver Lake, Big Creek, Squaw Valley and Dunlap, and it also bars them on any parcel under two acres served by a private well and septic system; the county's ADU page and its June 2026 handout F417 still say ADUs are 'currently not allowed within low water areas'. Where ADUs are allowed, a single-family lot may have one detached unit, either the state-model 'Limited Detached' unit (800 sq ft or less, 16 feet, 4-foot side and rear setbacks) or a larger unit under the 834.4.030.B.7 size limits, together with one JADU or one attached ADU. State law reaches further than the county text: Gov. Code 66323(a) requires ministerial approval of the state-exempt units (a conversion ADU, a JADU and an 800 sq ft detached unit) in any residential or mixed-use zone 'notwithstanding Sections 66314 to 66322', and HCD's March 2026 handbook says water-and-sewer area designations under 66314(a) 'cannot preclude units described in Government Code section 66323', so under state law the ban can lawfully reach only the larger county-standard units; no HCD letter or county statement has tested this. Inside the Low Water Area the county's own alternative is a discretionary second dwelling unit (Director Review and Approval with an owner-occupancy covenant), not an ADU. Fresno County Zoning Ordinance (Ordinance Code Division 6) § 834.4.030.B (intro), B.3, B.4.b, B.5.a-c, B.7.a (Ord. T-099-385, 2024, as amended by Ord. T-104-390, eff. 3-12-2026); § 834.4.030.C; Tables 2-2, 2-4, 2-4-1, 2-6; Gov. Code §§ 66314(a), (b)(1), 66323(a); HCD ADU Handbook (March 2026), 'Must ADUs be allowed jurisdiction-wide?'Full rules for Fresno County Ordinance read September 2026 | Attached ADUs (new space sharing a wall, floor or ceiling with the home) and converted ADUs (space inside the home, an attached garage or an existing accessory structure, plus up to 150 sq ft for entry) need only a building permit in the same zones, and fall under the same Low Water Area and under-two-acre well-and-septic prohibitions, as detached units (834.4.030.B.3-4). On a single-family lot the county allows only one attached or converted ADU or one JADU, plus one detached ADU (834.4.030.B.5.b-c), whereas Gov. Code 66323(a)(1)-(2) requires allowing a conversion ADU and a JADU and a new detached unit together, which HCD's handbook describes as 'at least one ADU constructed from existing space, one JADU, and one newly constructed detached ADU'. In an existing multifamily building, ADUs may be carved from non-livable space such as storage rooms, garages, attics or basements, at least one and up to 25 percent of the existing units (834.4.030.B.5.d(1), matching 66323(a)(3)). JADUs of up to 500 sq ft inside a single-family home, with an efficiency kitchen, are allowed with a ministerial building permit and a recorded deed restriction (834.4.030.B.4.c, B.9). The same state-law override described for detached units applies: in residential and mixed-use zones the conversion ADU and the JADU are 66323 units that area designations cannot preclude. Fresno County Zoning Ordinance § 834.4.030.B.3, B.4.a, B.4.c, B.5.b(1), B.5.c, B.5.d(1), B.8, B.9 (Ord. T-099-385 as amended by Ord. T-104-390); Gov. Code §§ 66323(a)(1)-(3), 66333; HCD ADU Handbook (March 2026), '66323 Units'Full rules for Fresno County Ordinance read September 2026 | 850 sq ft (0-1 bedroom) or 1,000 sq ft (2 bedrooms, the most allowed), also capped at 50% of the main home but never below 800 sq ft under state law; 800 sq ft state-exempt detached unit; conversions uncapped; JADU 500 sq ft; 16 ft single story (two-story detached only in AE, AL, A-2, R-R, R-C, R-S) | Not required | 1 space per new attached or detached ADU (tandem on the driveway allowed) unless within 1/2 mile walk of transit or another state exemption; none for conversions, JADUs or, under state law, the 800 sq ft state-exempt detached unit; no garage replacement | Permitted use |
| Fullerton | Allowed | Allowed | 1,200 sq ft detached; attached 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); conversions inside the home uncapped; 16 ft detached (18 ft near transit), 25 ft attached | Not required | 1 space per ADU with a bedroom unless exempt; none for studios, JADUs, conversions, state-exempt units, or within 1/2 mile of transit | Permitted use |
| Garden Grove | Allowed | Allowed | 850 sq ft studio/1-bed, 1,200 sq ft 2+ bed (attached: also max 50% of the home, but 800 sq ft always allowed); conversions uncapped; 800 sq ft state-exempt detached unit; JADU 500 sq ft; height 16 ft detached (18 ft near major transit), 25 ft attached | Not required | 1 space per new attached or detached ADU unless within 1/2 mile walking distance of transit or another state exemption; none for conversions, JADUs or state-exempt units; lost garage spaces need not be replaced | Permitted use |
| Glendale | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) for new ADUs; attached also capped at 50% of the home above 800 sq ft; 800 sq ft state-exempt detached unit; JADU 500 sq ft; 16 ft detached (18 ft near major transit), 25 ft attached | Not required | Max 1 space per ADU (or per bedroom if fewer); none within 1/2 mile walk of public transit, for conversions, state-exempt units, JADUs, historic properties, car-share or permit-parking areas, or with a new home; no garage replacement | Permitted use |
| Hayward | Allowed | Allowed | 1,200 sq ft detached (interior livable space); attached addition 50% of the main home but at least 800 sq ft; conversions uncapped; JADU 500 sq ft; detached height 16 ft (18 ft near transit) | Not required | None (no local ADU parking standard since Ord. 24-01; no replacement parking for converted or demolished spaces) | Permitted use |
| Hemet | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space, attached or detached; attached additions also capped at 50% of the home (800 sq ft state floor); 800 sq ft state-exempt detached; JADU 500 sq ft | Not required | Generally none; at most 1 space (per unit or bedroom, whichever is less) may be required for a new detached ADU outside the state exemptions | Permitted use |
| Hesperia | Allowed | Allowed | Detached 1,200 sq ft of livable floor area; attached 50 percent of the house up to 1,000 sq ft, with an 800 sq ft unit always allowed; JADU 500 sq ft; 150 sq ft minimum; height 16 ft detached (18 ft near major transit or beside a multistory multifamily building, plus 2 ft for a matching roof pitch near transit), 25 ft or two stories attached | Not required | None for ADUs; converted or demolished garage spaces need not be replaced (a local JADU garage-replacement rule conflicts with state law) | Permitted use |
| Huntington Beach | Allowed | Allowed | 1,200 sq ft detached; attached up to 50% of the existing home but at least 800 sq ft; 800 sq ft state-exempt detached unit and conversions always allowed; JADU 500 sq ft (codified 650 sq ft cap void) | Not required | At most 1 space per ADU (none for studios) where no state exemption applies; none within 1/2 mile walk of transit, for conversions, or for state-exempt units; no garage replacement; coastal-zone lots unsettled (codified text asks for 4 on-site) | Outside the coastal zone ADUs and JADUs get ministerial building-permit review with no hearing: the city says it 'provides ministerial review for all JADUs and ADUs', and Gov. Code 66317(a) requires a completeness determination within 15 business days and approval or denial within 60 days of a complete application, failing which the application is deemed approved. Inside the coastal zone (CZ overlay, HBZSO Chapter 221) the city page warns that ADUs 'may require Coastal Development Permits', and the certified LCP requires a public hearing before any CDP action (245.18), taken by the Zoning Administrator when no other discretionary approval is involved (245.16) and appealable to the Planning Commission and the City Council (245.32). Gov. Code 66329(a) requires a CDP decision on an ADU within 60 days and says no hearing is required, yet the city still holds one, and on 9-8-2026 the Planning Commission voted 4-2 on a council member's appeal to deny CDP No. 26-006 for two state-exempt detached ADUs at 205 Pecan Avenue that staff and the Zoning Administrator had approved under 66323. In the uncertified Sunset Beach specific plan area (SP17) the city's Sunset Beach Local Coastal Program Review Board grants an 'Approval in Concept' and the Coastal Commission issues the coastal permit. Gov. Code §§ 66317(a), 66329(a); HBZSO §§ 245.08, 245.16, 245.18, 245.32; City of Huntington Beach ADU page; Planning Commission action on Legistar file 26-708 (9-8-2026); Sunset Beach Local Coastal Program Review Board files 25-183 and 26-314Full rules for Huntington Beach Ordinance read September 2026 |
| Inglewood | Allowed | Allowed | Detached 1,000 sq ft, or the home's size if smaller (never below 850 sq ft, or 1,000 with 2+ bedrooms); attached 850 sq ft or 50% of the home (the city applies whichever is greater; the code text says whichever is less); 800 sq ft state-exempt detached unit always allowed; conversions uncapped; JADU 500 sq ft; detached 16 ft and one story (state floor 18 ft near major transit) | Not required | One space per ADU (tandem on the driveway allowed) unless a state exemption applies (half-mile walk to public transit including bus stops, conversions and units inside the home or an accessory structure, car share within a block, permit-parking areas); none for state-exempt units or JADUs; garage spaces lost to an ADU need not be replaced | Permitted use |
| Irvine | Allowed | Allowed | 1,200 sq ft detached; attached up to 50% of the existing home but at least 800 sq ft; 800 sq ft state-exempt detached unit; conversions of existing space not size-capped; JADU 500 sq ft | Not required | 1 space per ADU with a bedroom (none for studios) unless a state exemption applies (within 1/2 mile walking distance of transit, unit within the home or an accessory structure, state-exempt 66323 units); converted garages need no replacement | Permitted use |
| Jurupa Valley | Allowed | Allowed | 850 sq ft (1,000 sq ft with 2+ bedrooms) of interior livable space; attached to an existing home 50% of its floor area (800 sq ft state floor); 800 sq ft state-exempt detached; conversions uncapped; JADU 500 sq ft; 16 ft detached, 25 ft attached | Not required | 1 space per local-track ADU unless exempt (within 1/2 mile walk of transit, part of the home or an accessory structure, historic district, car share, built with a new home); none for state-exempt units or JADUs | Permitted use |
| La Mesa | Allowed | Allowed | 1,200 sq ft detached, plus an 800 sq ft state-exempt detached unit; attached up to 50 percent of an existing home and 1,200 sq ft (800 sq ft always allowed); JADU 500 sq ft; 20 ft to the plate line in single-family zones | Not required | None | Permitted use |
| Laguna Niguel | Allowed | Allowed | Class 2 (local track): 850 sq ft studio or 1-bedroom, 1,000 sq ft 2+ bedrooms (interior livable space); attached also 50% of the existing home, never below 800 sq ft. Class 1 (state-exempt): 800 sq ft detached, conversions uncapped; JADU 500 sq ft. Height 16 ft detached (18 to 20 ft near major transit), 25 ft attached | Not required | One space per local-track (Class 2) ADU or per bedroom, whichever is less, waived within 1/2 mile walking distance of public transit and under the other Gov. Code 66322(a) exemptions; none for state-exempt (Class 1) units or JADUs; no garage replacement | Permitted use |
| Lake Forest | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space for Class 2 units, attached also capped at 50% of the home but never below 800 sq ft; 800 sq ft Class 1 detached; conversions uncapped (+150 sq ft for access); JADU 500 sq ft; 16 ft detached (18 ft near major transit), 25 ft attached, two stories | Not required | 1 space per new Class 2 ADU (or per bedroom if fewer) unless within 1/2 mile walking distance of public transit or another state exemption applies; none for Class 1 (state-exempt) units, conversions or JADUs; no replacement of lost garage spaces | Permitted use |
| Lancaster | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) / 1,200 sq ft (2+ bedrooms), as the city applies them to attached and detached ADUs (the code has had no cap for single-family detached ADUs since 2025); conversions uncapped; JADU 500 sq ft; 18 ft detached (20 ft with matching roof pitch), 25 ft and 2 stories attached | Not required | 1 space (10 x 20 ft, tandem allowed) for a new ADU over 800 sq ft (city form: over 850 sq ft) beyond a half-mile walk of public transit, bus stops included; none for conversions, JADUs, 800 sq ft exempt units or other Gov. Code 66322 cases | Permitted use |
| Long Beach | Allowed | Allowed | Detached new construction: 800 sq ft (single-family lot). Attached new construction: 50% of primary dwelling size or 800 sq ft, whichever is more. Conversions of existing primary-dwelling space or accessory buildings: no size limit (accessory-building conversions may add only a 150 sq ft ingress/egress addition). JADU: 500 sq ft max. Minimum for any ADU or JADU: 150 sq ft (efficiency unit). Multifamily lots: up to 8 detached ADUs (or the number of existing permitted units, whichever is less) and attached conversions (1 ADU or 25% of existing units, whichever is more), no stated size limits. | Not required | At most 1 space per ADU or per bedroom, whichever is less, with tandem parking on a driveway allowed (state cap the city applies). No parking required for: ADUs within a half-mile walking distance of a transit stop; ADUs in a historic district; ADUs converted from part of the primary dwelling or an accessory building; where on-street permits are required but not offered to the ADU occupant; ADUs within a half-mile of a car share vehicle; ADUs in the citywide Parking Exempt Area (LBMC 21.41.175); and all JADUs. Replacement parking cannot be required when a garage, carport, or covered space is demolished or converted for an ADU. | Permitted use |
| Los Angeles | Allowed | Allowed | 1,200 sq ft (detached, also capped at 2 stories); attached capped at 50% of the existing primary dwelling's floor area, but an attached ADU under 850 sq ft (under 1,000 sq ft with more than one bedroom) is always allowed; no 50% cap when the ADU is attached to a new dwelling | Not required | 1 space per ADU, but waived if within 1/2 mile walking distance of public transit, within one block of a car-share location, in a designated historic district, or if the ADU is part of the proposed or existing primary residence or an accessory structure; no replacement parking when a garage or carport is demolished or converted for the ADU | Permitted use |
| Los Angeles County | Allowed | Allowed | 1,200 sq ft (attached or detached); no cap for conversions within existing space; 800 sq ft state-exempt detached unit always allowed; JADU 500 sq ft; 25 ft height (750 sq ft in the Santa Monica Mountains Coastal Zone) | Not required | None outside Very High Fire Hazard Severity Zones; 1 uncovered space per ADU inside a VHFHSZ unless an exemption applies; none for JADUs | Permitted use |
| Menifee | Allowed | Allowed | 1,500 sq ft attached or detached (no percent-of-house cap); 800 sq ft state-exempt detached unit; JADU 500 sq ft; height 18 ft detached (20 ft near major transit), 25 ft attached | Not required | 1 space per new attached or detached ADU unless exempt; none for conversions, state-exempt units or JADUs | Permitted use |
| Mission Viejo | Allowed | Allowed | 1,200 sq ft detached (city guide: 850 for a studio or 1-bedroom); attached 50% of the home; conversions uncapped; JADU 500 sq ft | Not required | 1 space per new attached or detached ADU unless exempt; none for conversions or JADUs | Permitted use |
| Modesto | Allowed | Allowed | 1,200 sq ft detached (and no larger than the house); attached 50% of the house; state law guarantees at least 800 sq ft either way (HCD: 850, or 1,000 with 2+ bedrooms); conversions uncapped (+150 sq ft for access); JADU 500 sq ft; detached 16 ft (18 ft near major transit, +2 ft for matching roof pitch), attached 25 ft or zone limit, 2 stories | Not required | 1 space for a new ADU with a bedroom (none for studios), tandem or uncovered on the driveway allowed, unless exempt: within 1/2 mile walk of public transit (bus stops count), historic district, within the house or an accessory structure, permit-parking area, car share within 1 block, or filed with a new home; none for JADUs or state-exempt units; no replacement for converted or demolished garages | Permitted use |
| Monterey | Allowed | Allowed | 850 sq ft (studio or one bedroom) or 1,000 sq ft (more than one bedroom), attached or detached; 800 sq ft for a new detached ADU paired with a JADU (state-exempt unit); conversions of existing space uncapped (up to 150 sq ft added for access); JADU 500 sq ft; height 16 ft detached (18 ft near major transit or on a multistory multifamily lot, up to 20 ft to match the house's roof pitch), attached 25 ft or the zone limit, two stories max | Not required | 1 space per new ADU (per unit or per bedroom, whichever is less; tandem or setback parking allowed) unless exempt: within 1/2 mile walking distance of public transit, within 1 block of car share, conversions, historic districts, permit-parking areas; none for state-exempt units or JADUs; no replacement for a demolished or converted garage or carport | Permitted use |
| Monterey County | Allowed | Allowed | 1,200 sq ft (1,000 sq ft in the Big Sur coast and coastal B-8 areas); JADU 500 sq ft; inland resource-constrained areas limited to the state-exempt 800 sq ft detached unit or conversions; coastal in-home conversions capped at 50% of the house; detached height 16 ft (18 ft on multifamily lots or near transit, plus 2 ft for a matching roof pitch) | Not required | None, except 1 space per ADU on a few coastal Carmel Point lots mapped in CIP Appendix 15 (where the home's own required parking must also stay); JADUs never | Permitted use |
| Moreno Valley | Allowed | Allowed | Detached: 1,000 sq ft, with no maximum on a parcel with a multifamily structure. Attached: 850 sq ft for an efficiency or one bedroom and 1,000 sq ft for two or more bedrooms where there is an existing single-family home; Table E-1 also caps attached units at 50% of the primary dwelling while always permitting 1,000 sq ft. Conversions of existing accessory structures or primary-dwelling space: no size limit. JADU: 150 sq ft minimum, 500 sq ft interior livable space maximum. By-right new detached unit on a single-family lot (Gov. Code 66323 pathway): 800 sq ft with 4 ft side and rear setbacks. | Not required | One space per ADU or per bedroom, whichever is less, which may be tandem on a driveway. No replacement parking when a garage, carport, covered structure or uncovered space is demolished or converted for an ADU. Exempt: ADUs within one-half mile of a public transportation stop, within one block of a car-share space, in a designated historic district, where on-street permits are not offered to ADU occupants, or that are part of an existing dwelling or existing accessory structure; state law adds ADUs applied for together with a new single-family or multifamily dwelling. JADUs within the living area are exempt; a garage converted to a JADU triggers the standard requirement. | Permitted use |
| Murrieta | Allowed | Allowed | 1,200 sq ft detached; attached 50% of the home (800 sq ft floor); JADU 500 sq ft | Not required | 1 space per ADU unless exempt (transit, conversions, JADUs, state-exempt units) | Permitted use |
| Nevada County | Allowed | Allowed | 1,200 sq ft detached; attached 50% of the existing home up to 1,200 sq ft (800 sq ft state floor); measured from interior walls; JADU 500 sq ft; tiny home on wheels 400 sq ft | Not required | None (ADUs and JADUs, countywide) | Permitted use |
| Newport Beach | Allowed | Allowed | 850 sq ft (studio or one bedroom) or 1,000 sq ft (two or more bedrooms) for new attached or detached ADUs; conversions uncapped; JADU 500 sq ft; at least 800 sq ft allowed despite floor area, coverage or front setback limits; detached height 16 ft (18 ft near major transit or beside multistory multifamily) | Not required | 1 space per new attached or detached ADU unless exempt (transit within 1/2 mile, conversions and others); none for JADUs; the coastal zone also requires replacement of demolished or converted garage parking | Permitted use |
| Norwalk | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) for local-standards ADUs, attached also capped at 50% of the home (state law still guarantees 800 sq ft); 800 sq ft for the state-exempt detached ADU; conversions of existing space uncapped; JADU 500 sq ft; 150 sq ft minimum; detached 16 ft (18 ft plus 2 ft roof pitch near major transit), attached 25 ft | Not required | 1 off-street space per local-standards ADU (tandem on the driveway allowed) unless within 1/2 mile walk of public transit or another state exemption applies; none for JADUs, state-exempt units or ADUs inside the home or an accessory structure; lost garage or carport spaces need not be replaced | Permitted use |
| Oakland | Allowed | Allowed | Detached (Category Two): 850 sq ft for a studio or 1-bedroom, 1,000 sq ft for 2 or more bedrooms. Attached Category Two: whichever is greater of those caps or 50% of the primary residence's floor area, but never more than 1,200 sq ft. Category One conversions: the existing envelope plus up to 150 sq ft for ingress and egress (a larger expansion caps the total at 850 or 1,000 sq ft and must meet setbacks). JADU: 500 sq ft. | Not required | One space per ADU (tandem allowed), but none if the ADU is within a half-mile walk of a public transit stop, on any lot in a City of Oakland Area of Primary or Secondary Importance (historic areas), in a permit-parking area where permits are not offered to ADU occupants, within one block of a carshare vehicle, or part of the existing or proposed main home or an accessory structure. JADUs never need parking. No replacement parking is required when a garage or other space is removed to build an ADU. | Permitted use |
| Oceanside | Allowed | Allowed | 1,200 sq ft detached; attached up to 50% of the existing home but at least 800 sq ft; 800 sq ft state-exempt detached unit; conversions not size-capped; JADU 500 sq ft | Not required | At most 1 space per ADU or per bedroom, whichever is less (state cap; none for studios); none within 1/2 mile walking distance of transit, for units within the home or an accessory structure, for state-exempt units or JADUs; lost garage spaces need no replacement | Permitted use |
| Ojai | Allowed | Allowed | 1,200 sq ft or 85% of the main home, whichever is smaller (floors: 850 sq ft one bedroom, 1,000 sq ft two or more bedrooms, 800 sq ft any ADU); JADU 500 sq ft; ADUs on multifamily lots 800 sq ft | Not required | None for most ADUs; one uncovered space (tandem allowed) only for a new detached ADU or home split more than 1/2 mile from a transit stop and outside a historic district | An ADU that meets Table A 'shall be approved ministerially by the Community Development Director, without discretionary review and a hearing' (§ 10-2.1709(c)) through a zoning clearance with the building permit: the city's ADU packet uses the Zoning Clearance for a Building Permit form, and a detached 740 sq ft ADU went through Zone Clearance ZCL 26-028 in September 2026. Table A, however, requires a Design Review Permit 'only for two-story units, units taller than 24 ft, or units on the second story' (and for home splits that expand the home more than 10 percent), and design review permits are Planning Commission decisions on subjective compatibility findings at a public hearing (§§ 10-2.2003(a), (c), 10-2.2009). Development on slopes of 15 percent or more also needs a design review permit unless exempt (§ 10-2.1103), and work on designated landmarks or in historic districts needs a Chapter 4-8 work permit (major work permits from the Historic Preservation Commission). These discretionary steps conflict with Gov. Code 66316 and 66317(a)(1), and for attached units up to 25 ft and two stories with 66321(b)(4)(D); no two-story ADU design review appeared on 2025-2026 Planning Commission agendas, so how the city applies them today is undocumented. Ojai Municipal Code § 10-2.1709(c), (d) Table A ('Design Review Permit Required'), (e); §§ 10-2.1103(a), 10-2.2003, 10-2.2009; Chapter 4-8 (work permits); Gov. Code §§ 66316, 66317(a), 66321(b)(4)(D)Full rules for Ojai Ordinance read October 2026 |
| Ontario | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space; attached also capped at 50% of the home (never below 800 sq ft); state-exempt detached unit 800 sq ft; JADU 500 sq ft; detached 16 ft and one story on the local track | Not required | 1 space per ADU or per bedroom (whichever is less) for locally regulated (Class 2) ADUs, waived within 1/2 mile walk of public transit and for units inside the home or an accessory structure; none for state-exempt units or JADUs; no replacement parking | Permitted use |
| Orange | Allowed | Allowed | 850 sq ft (0-1 bedroom) or 1,000 sq ft (2+ bedrooms), up to 50% of the existing home with 800 sq ft always allowed; conversions limited to existing space plus 150 sq ft; JADU 500 sq ft; 16 ft detached (18 ft near major transit), 25 ft attached | Not required | 1 space per ADU or per bedroom, whichever is less, unless exempt (public transit within 1/2 mile, historic district, conversions, state-exempt units); none for JADUs | Permitted use |
| Orange County | Allowed | Allowed | 1,200 sq ft interior livable space (attached: 50% of the home, 800 sq ft always allowed); conversions up to the existing structure; JADU 500 sq ft; 16 ft in side/rear setbacks (18 ft near major transit, 25 ft attached), base-zone height (35 ft) elsewhere | Not required | 1 space per new detached ADU unless exempt (1/2 mile walk to public transit incl. bus stops, historic district, permit-parking area, car share within a block, studio); none for attached or converted ADUs or JADUs | Permitted use |
| Oxnard | Allowed | Allowed | Detached 850 sq ft (one bedroom or less) or 1,200 sq ft (more than one bedroom); attached 1,200 sq ft or 50% of the home, whichever is less, never below 800 sq ft; 800 sq ft state-exempt detached unit (16 ft); JADU 500 sq ft; otherwise 2 stories and 25 ft | Not required | None for state-exempt units (800 sq ft detached, conversions, multifamily ADUs), internal ADUs and JADUs; otherwise 1 space per attached or detached ADU unless within half a mile walking distance of public transit or another state exemption applies | Permitted use |
| Palm Springs | Allowed | Allowed | 850 sq ft (studio/1-bed) or 1,000 sq ft (2+ bed) of interior livable space for permit-track ADUs, attached also 50% of the home (800 sq ft floor); 800 sq ft state-exempt detached; conversions uncapped; JADU 500 sq ft; 16 ft detached | Not required | None for state-exempt units, conversions and JADUs; 1 space per permit-track ADU or bedroom, whichever is less (none for studios), unless near transit or otherwise exempt | Permitted use |
| Palmdale | Allowed | Allowed | 1,200 sq ft detached; attached the greater of 850 sq ft (0-1 bedroom) or 1,000 sq ft (2+ bedrooms) and 50% of the existing home; JADU 500 sq ft; height 16 ft detached (18 ft near major transit or on multistory multifamily lots), 25 ft attached | Not required | 1 space for an ADU with a bedroom (none for studios); none within 1/2 mile walk of public transit, in historic districts, for units inside the home or an accessory structure, near car share, where street permits are not offered, or when filed with a new home; none for JADUs; no replacement parking | Permitted use |
| Pasadena | Allowed | Allowed | Detached 1,200 sq ft; attached 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); 800 sq ft Exemption ADU on any lot; conversions uncapped; JADU 500 sq ft; Hillside Overlay: detached 1,000 sq ft, and 800 sq ft on streets 26 ft wide or narrower; height 18 ft detached (16 ft in hillside, visible historic-district and front-yard cases), 25 ft attached | Not required | None for most ADUs; 1 space only for a non-exemption ADU (new construction over 800 sq ft) on a single-family lot outside the exemptions | Permitted use |
| Pismo Beach | Allowed | Allowed | Coastal zone: 850 sq ft (studio or 1-bed) or 1,000 sq ft (2-bed), or 50% of the home if smaller, 800 always allowed; inland (state law): 1,200 sq ft detached, attached 50% (800 floor); conversions uncapped; JADU 500 | Not required | Coastal zone: 1 space (studio or 1-bed) or 2 (2-bed) unless a state exemption applies; no exemptions west of US 101 within 1/4 mile of beach access; inland at most 1; JADUs none | Permitted use |
| Pittsburg | Allowed | Allowed | 1,200 sq ft detached; attached 50% of the home up to 1,200 sq ft, with 850 sq ft (1,000 sq ft for 2+ bedrooms) always allowed; 800 sq ft state-exempt unit; JADU 500 sq ft; 16 ft detached (18 ft near major transit), 25 ft attached | Not required | 1 space per ADU (tandem allowed) unless exempt; none for JADUs, conversions, state-exempt units, or within 1/2 mile walking distance of public transit | Permitted use |
| Pomona | Allowed | Allowed | 1,200 sq ft on lots of 7,200 sq ft or more; 850 sq ft (studio or 1-bed) or 1,000 sq ft (2+ bed) on smaller lots; interior livable space, attached or detached; 800 sq ft state-exempt detached unit; JADU 500 sq ft; detached height 16 ft | Not required | None (no parking required for any ADU; garage, carport or covered spaces lost to an ADU need not be replaced) | Permitted use |
| Rancho Cucamonga | Allowed | Allowed | 1,200 sq ft detached; attached 50% of the home or 1,200 sq ft, whichever is less (state law guarantees 800 sq ft); 800 sq ft state-exempt detached unit; JADU 500 sq ft; height 16 ft detached (18 ft near major transit, 20 ft there to match the roof pitch; 18 ft with a multistory multifamily building), 25 ft attached | Not required | 1 space for a new detached ADU unless exempt (e.g., within a 1/2-mile walk of public transit); none for attached or conversion ADUs, state-exempt units or JADUs; no replacement of garage spaces lost to an ADU | Permitted use |
| Rancho Santa Margarita | Allowed | Allowed | Detached 1,200 sq ft; attached 1,200 sq ft or 50% of the primary dwelling, whichever is less, never below 800 sq ft; conversions uncapped; JADU 500 sq ft; detached height 16 ft (18 ft near major transit or beside a multistory multifamily building, plus 2 ft for roof pitch) | Not required | 1 space for a new attached or detached ADU unless exempt; none for state-exempt (Gov. Code 66323) units, conversions, JADUs, ADUs filed with a new dwelling, or within 1/2 mile of transit | Permitted use |
| Rialto | Allowed | Allowed | 850 sq ft (1,000 sq ft with 2+ bedrooms) or 50% of the home if larger, never over 1,200 sq ft; 800 sq ft state-exempt detached unit; JADU 500 sq ft; height 16 ft / one story locally (state floors 18 ft near transit, 25 ft attached) | Not required | 1 space per ADU (or per bedroom if fewer); none within 1/2 mile of transit, for conversions, JADUs or state-exempt units | Permitted use |
| Richmond | Allowed | Allowed | 850 sq ft (studio/1 bedroom) or 1,000 sq ft (2+ bedrooms) interior livable space; 800 sq ft state-exempt detached unit; conversions uncapped; JADU 500 sq ft; detached 16 ft (18 ft near major transit, +2 ft roof pitch), attached 25 ft or zone height, max two stories | Not required | 1 space per new local-track ADU with a bedroom (studios none), waived within 1/2 mile of public transit and in the other state exemptions; none for state-exempt units, conversions or JADUs | Permitted use |
| Riverside | Allowed | Allowed | Attached ADU: 50 percent of the existing or proposed primary dwelling floor area or 1,200 sq ft, whichever is less, but never less than 850 sq ft (one bedroom or less) or 1,000 sq ft (more than one bedroom); detached ADU: 1,200 sq ft; JADU: 500 sq ft; movable ADU (MADU): 150 to 430 sq ft; minimum for any ADU or JADU is an efficiency unit under California Building Code Section 1208.4 | Not required | None; no parking is required for any ADU, MADU or JADU, and no replacement parking is required when a garage, carport or covered parking serving the primary dwelling is converted to an ADU | Permitted use |
| Riverside County | Allowed | Allowed | 1,600 sq ft detached on single-family lots; attached 50% of the home or 1,600 sq ft, whichever is less, but never below 1,000 sq ft; 150 sq ft minimum; JADU 500 sq ft; height 16 ft detached (18 near major transit or on multistory multifamily lots), 25 ft attached | Not required | 1 space per ADU or per bedroom, whichever is less (tandem or in setbacks allowed); none for JADUs, ADUs inside an existing or proposed home or accessory structure, within 1/2 mile walking distance of transit, in historic districts, where on-street permits aren't offered, or near car share; no replacement for converted garages | Permitted use |
| Roseville | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space; attached and in-home units also max 50% of the home, never below 800 sq ft; state-exempt detached unit 800 sq ft; JADU 500 sq ft | Not required | 1 space for a new ADU with 1+ bedrooms; none for studios, conversions, JADUs, or units within 1/2 mile walking distance of public transit and the other state exemptions | Permitted use |
| Sacramento | Allowed | Allowed | 1,200 sq ft detached (one unit, or the combined total of two detached units) under the local option; attached: the greater of 50% of the primary dwelling or 850 sq ft (one bedroom or less) / 1,000 sq ft (more than one bedroom); 800 sq ft for a detached unit under the state option; JADU 500 sq ft | Not required | None. Sacramento has no minimum off-street vehicle parking requirement for any land use citywide; the ADU section imposes no parking and the bicycle parking table sets no minimum for ADUs or JADUs. | Permitted use |
| Sacramento County | Allowed | Allowed | 1,200 sq ft detached; attached the greater of 50% of the home, 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); conversions: existing space plus 150 sq ft for access; JADU 500 sq ft (plus 150 sq ft for access when converted); no ADU larger than the main home. Height 16 ft detached (18 ft within 1/2 mile of a major transit stop or to match the home's roof pitch), 25 ft attached, 18 ft detached on multifamily lots | Not required | 1 space only for a new detached ADU over 800 sq ft on a single-family or halfplex lot, unless within 1/2 mile walking distance of transit or another exemption applies; none for ADUs of 800 sq ft or less, attached or conversion ADUs, multifamily ADUs or JADUs; no replacement parking for converted or demolished garages, carports or spaces | Permitted use |
| Salinas | Allowed | Allowed | Detached: 1,200 sq ft; attached addition: 50% of the existing home, never below 850 sq ft (1,000 sq ft with 2+ bedrooms); 800 sq ft state-exempt detached unit; JADU 500 sq ft; height 16 ft detached (18 ft near major transit, plus 2 ft for a matching roof pitch), 25 ft and 2 stories attached | Not required | At most 1 space per ADU (or per bedroom if fewer); none within 1/2 mile walking distance of public transit, for conversions, state-exempt units or JADUs; no replacement parking | Permitted use |
| San Bernardino | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space; attached also capped at 50% of the home (never below 800 sq ft); state-exempt detached unit 800 sq ft; JADU 500 sq ft; detached 16 ft, one story on the local track | Not required | 1 space per ADU or per bedroom (whichever is less) for locally regulated ADUs, waived within 1/2 mile walk of transit and for units inside the home or an accessory structure; none for state-exempt units or JADUs; no replacement parking | Permitted use |
| San Bernardino County | Allowed | Allowed | 1,200 sq ft attached or detached (attached also capped at 50% of an existing home, never below 800 sq ft of livable space); no cap on conversions of existing space; JADU 500 sq ft; minimum 200 sq ft (JADU 150) except efficiency units; detached 18 ft (+2 ft to match roof pitch), attached 25 ft, 2 stories max | Not required | 1 uncovered space per ADU in the county table (tandem on a driveway allowed; state law caps it at one per unit or per bedroom, whichever is less, so a studio may owe none), waived within 1/2 mile walk of public transit, for units inside the home or a converted accessory structure and in the other state-law cases; none for JADUs; no replacement for converted or demolished garages | Permitted use |
| San Carlos | Allowed | Allowed | No fixed cap: up to 50% of an existing home and the lot's floor-area limit (state floor 850 sq ft, 1,000 with 2+ bedrooms); 800 sq ft always allowed; conversions uncapped; JADU 500 sq ft | Not required | 1 space per ADU unless exempt (within 1/2 mile walk of public transit, conversions, others); none for JADUs | Permitted use |
| San Clemente | Allowed | Allowed | 850 sq ft (studio or one bedroom) or 1,000 sq ft (two or more bedrooms) of interior livable space for new attached or detached ADUs; at least 800 sq ft always allowed; conversions of existing space uncapped; JADU 500 sq ft; detached height 16 ft (18 ft beside a multistory multifamily building or near major transit, plus 2 ft for a matching roof pitch), attached per zone height | Not required | 1 space per ADU unless exempt (within 1/2 mile walking distance of public transit, which includes SC Rides pickup points; conversions and units inside a proposed home; historic district or Architectural overlay; car share; permit parking; outside the coastal zone also ADUs built with a new home); none for JADUs; demolished or converted garage parking need not be replaced outside the coastal zone | Permitted use |
| San Diego | Allowed | Allowed | 1,200 sq ft gross floor area for a new attached or detached ADU; no maximum for an ADU inside an existing or proposed house, inside an existing accessory structure (plus up to 150 sq ft for entry and exit), or inside an existing multifamily building; 150 sq ft minimum; JADU 150 to 500 sq ft | Not required | None for ADUs or JADUs, with one exception: one off-street space per ADU when the lot is inside the Beach Impact Area of the Parking Impact Overlay Zone and outside a transit priority area, waived if the ADU is 500 sq ft or less, attached, in a designated historical district, in a residential permit parking district, or within one block of a car share vehicle. Affordable and bonus ADUs under the ADU Home Density Bonus Program need one space each outside transit priority areas. | Permitted use |
| San Diego County | Allowed | Allowed | 1,200 sq ft detached (25 ft tall); attached 50% of the house up to 1,200 sq ft, with 850 sq ft (1,000 sq ft with 2+ bedrooms) always allowed; 800 sq ft / 18 ft state-exempt detached unit; conversions of existing space uncapped; JADU 500 sq ft; measurement basis disputed (ordinance: exterior walls; HCD and PDS-611: interior livable space) | Not required | 1 space for a new detached ADU, waived within 1/2 mile of public transit and in the other state exemption cases; none for attached or converted ADUs, 800 sq ft state-exempt units, or JADUs (county text still requires replacing garage spaces lost to a JADU conversion, which HCD found unlawful in July 2026) | Permitted use |
| San Francisco | Allowed | Allowed | State program: detached ADU on a single-family lot 850 sq ft (studio or one bedroom) or 1,000 sq ft (two or more bedrooms); detached ADUs on multifamily lots have no size cap; attached ADU capped at the greater of 50% of the existing home or 850/1,000 sq ft; JADU 500 sq ft. Local program: no fixed cap (limited by the buildable area or the existing built envelope), except the rear-yard detached ADU at 850/1,000 sq ft | Not required | No; additional parking is not required for an ADU. When a garage, carport, or covered parking structure is demolished or converted to build a state-program ADU, the lost off-street spaces do not have to be replaced | Permitted use |
| San Jose | Allowed | Allowed | 1,000 sq ft (lots up to 9,000 sq ft) or 1,200 sq ft (larger lots); attached ADUs also capped at 50% of primary dwelling; no cap for conversions of existing detached structures | Not required | None | Permitted use |
| San Juan Capistrano | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space for local-track ADUs, attached also 50% of the home with an 800 sq ft floor; 800 sq ft state-exempt detached unit; conversions uncapped; JADU 500 sq ft; detached 16 ft | Not required | None for state-exempt units, conversions and JADUs; one space per new local-track ADU unless exempt (transit within 1/2 mile, Los Rios and Mission Residential districts, car share); state cap means none for a studio | Permitted use |
| San Marcos | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms), attached or detached, and no more than 50% of the home's living area but never under 850 sq ft; 800 sq ft state-exempt detached unit; conversions of existing space uncapped; JADU 500 sq ft; height 16 ft detached (18 ft near major transit or on multistory multifamily lots, plus 2 ft for a matching roof pitch), 25 ft or 2 stories attached | Not required | 1 space for a new ADU unless exempt (none within a half-mile walk of public transit, for conversions, studios or state-exempt units); none for JADUs | Permitted use |
| San Rafael | Allowed | Allowed | 1,000 sq ft detached; attached 1,000 sq ft or 50% of the home, whichever is less, with 800 sq ft always allowed; conversions uncapped; JADU 500 sq ft | Not required | 1 space per new attached or detached ADU unless exempt; none for conversions, JADUs, state-exempt units or within 1/2 mile walking distance of transit | Permitted use |
| Santa Ana | Allowed | Allowed | 1,000 sq ft for a new attached or detached ADU; an attached ADU is also capped at 50% of the main home's habitable space but may always reach 800 sq ft; 800 sq ft when an ADU and a JADU are both on the lot; JADUs up to 500 sq ft; conversions of existing space have no size limit (an accessory-structure conversion may add up to 150 sq ft). Minimum size 220 sq ft. | Not required | 1 space per new ADU (tandem permitted; none for JADUs), waived if any exemption applies: within 1/2 mile walking distance of public transit, in a historic district, part of the existing or proposed main home or an existing accessory structure, on-street permits required but not offered to the ADU occupant, a car-share vehicle within one block, a studio with no bedroom, or an ADU applied for together with a new single-family or multifamily home on a lot that meets any other exemption. No replacement parking is required when a garage, carport or parking space is demolished or converted for the ADU. | Permitted use |
| Santa Barbara | Allowed | Allowed | Detached standard ADU 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) on lots under 15,000 sq ft, 1,200 sq ft on larger lots; attached addition 50% of the home's living area (800 sq ft always allowed); state-exempt 'special' detached unit 800 sq ft; conversions uncapped; JADU 500 sq ft; detached 18 ft plus 2 ft for roof pitch (special units one story, 16 ft in the Very High Fire Hazard Severity Zone), attached 25 ft | Not required | None for most ADUs and all JADUs; 1 space for a non-studio ADU in a High Fire Hazard Area unless within 1/2 mile of transit or another exemption applies; coastal zone: 1 uncovered space unless a single-home lot outside the West Beach, Lower State and East Beach access areas meets an exemption, and garage spaces lost to an ADU must be replaced | Permitted use |
| Santa Barbara County | Allowed | Allowed | 850 sq ft (0-1 bedroom) or 1,000 sq ft (2+ bedrooms) on lots up to 15,000 net sq ft; 1,200 sq ft on larger lots; attached also capped at 50% of the house; 800 sq ft state-exempt detached unit always allowed (16 ft, 18 ft near transit); in-home conversions uncapped on the state-exempt track (1,200 sq ft on the local track); multifamily detached ADUs 1,200 sq ft (HCD disputes); JADU 500 sq ft | Not required | None for state-exempt units (800 sq ft detached, conversions, multifamily ADUs), attached ADUs and JADUs; 1 space per new detached local-track ADU unless within 1/2 mile walk of public transit (a bus stop counts) or another state exemption applies; lost garage spaces need not be replaced, except on shoreline coastal lots and in Isla Vista south of El Colegio Rd | Permitted use |
| Santa Clara | Allowed | Allowed | Detached 1,000 sq ft on parcels of 5,500 sq ft or less, 1,200 sq ft on larger parcels; attached 1,000 sq ft or 50% of the home, whichever is less (800 sq ft floor); JADU 500 sq ft; conversions uncapped | Not required | None | Most ADUs are ministerial: the city 'shall ministerially approve' the listed single-family and multifamily categories 'through the issuance of a Zoning Clearance' (SCCC § 18.60.020.A-B, § 18.126.020.F-G), and the Planning Division says ADU and JADU projects 'can be submitted as a Building Permit, except for new attached second-story ADUs on a single-story residence, which would require an Architectural Review.' Any ADU outside the ministerial categories, including an attached ADU that does not match the height of the main home, must meet the Chapter 18.10 zone standards and 'undergo Architectural Review in compliance with Chapter 18.120' (§ 18.60.020.C and H): a Director decision on discretionary findings (neighborhood character, the 2014 Single-Family and Duplex Residential Design Guidelines), made at a noticed public Development Review Hearing for second-story additions and projects the Director refers (§ 18.120.020.D and F), and appealable to the Planning Commission. Development Review Hearing agendas show this routinely: PLN25-00227 and PLN25-00355 (second-story ADUs, approved 11-19-2025), PLN25-00194 (a 1,000 sq ft two-story attached ADU, 4-8-2026), PLN25-00483 (a second-floor ADU, 7-8-2026) and PLN26-00047 (an 882 sq ft one-story attached ADU, 9-16-2026, heard only because it was taller than the existing house). That track conflicts with Gov. Code § 66317(a)(1), which requires every ADU permit application to be 'considered and approved ministerially without discretionary review or a hearing', and with the 25-foot attached height floor in § 66321(b)(4)(D); no HCD letter has tested it. SCCC § 18.60.020.A, B, C, H; SCCC §§ 18.120.020.C-F, 18.126.020.F-G; Gov. Code §§ 66317(a)(1), 66321(b)(4)(D); Development Review Hearing staff reports PLN25-00227, PLN25-00355, PLN25-00194, PLN25-00483, PLN26-00047 (Legistar files 25-1101, 25-1564, 25-1742, 26-651, 26-884)Full rules for Santa Clara Ordinance read October 2026 |
| Santa Clara County | Allowed | Allowed | 1,200 sq ft detached; attached 800 sq ft (home up to 1,600 sq ft), 50% of the home (1,601-2,400 sq ft) or 1,200 sq ft (larger homes); conversions not size-capped (state law); JADU 500 sq ft; 16 ft where the ADU sits inside the zone's residential setbacks (state law: 18 ft near major transit plus 2 ft for roof pitch, 25 ft attached), otherwise the zone limit (35 ft in most districts) | Not required | 1 space per standard ADU unless exempt (within 1/2 mile of public transit, in a -h historic district, part of the existing home or an existing accessory structure, permit-parking areas, car share within one block, or applied for with a new home under state law); none for JADUs or movable tiny homes; no replacement for a converted garage or carport | Permitted use |
| Santa Clarita | Allowed | An ADU created inside the existing or proposed space of a single-family home or an existing accessory structure (a conversion, including an attached garage) is allowed ministerially, together with one JADU, and the city's FAQ sets no maximum size for it. The city's Director's Policy and March 2026 FAQ list only the state-exempt Gov. Code 66323 categories (conversion, detached new construction, JADU), and the FAQ dropped the 'Attached' row the 2023 handout carried, so a new attached addition to an existing home is not among the ADU types the city says it approves. HCD told the city on December 10, 2025 that it must also allow at least one ADU under the general state standards of Gov. Code 66314 (which include attached ADUs up to 50 percent of the existing home) in combination with the 66323 units; ask Planning (661-255-4330) before designing an attached addition. On multifamily lots, ADUs may be converted from non-livable space such as storage rooms, attics, basements or garages: at least one and up to 25 percent of the existing units. Gov. Code 66323(a)(1), (a)(3); Gov. Code 66314(d)(3)-(4); SCMC 17.57.040(L); Director's Policy (2-19-2026)Full rules for Santa Clarita Ordinance read October 2026 | Detached new-construction ADU: 800 sq ft of livable space. Conversion of existing space inside the home or an accessory structure: no maximum (an accessory-structure conversion may add up to 150 sq ft, only for ingress and egress). JADU: 500 sq ft, entirely within the home. | Not required | None. The city's March 2026 ADU FAQ states 'There are no parking requirements for ADUs or JADUs', and the code no longer sets any ADU parking standard. No replacement parking may be required when a garage or carport is converted or demolished for an ADU. | Permitted use |
| Santa Cruz | Allowed | Allowed | Nonexempt detached: greatest of 850 sq ft (studio or 1 bedroom), 1,000 sq ft (2+ bedrooms) or 10% of net lot area up to 1,200 sq ft; attached: greatest of 850/1,000 sq ft or 50% of the home's habitable area; state-exempt detached 800 sq ft; conversions any size (+150 sq ft); JADU 500 sq ft; all interior livable space; detached height 16 ft (22 ft with 4 ft setbacks) | Not required | None outside the Coastal Zone; in the Coastal Zone, 1 space per ADU (plus replacement of removed spaces) only in the mapped 'ADU Parking Required' areas near the shore; none for JADUs | Permitted use |
| Santa Maria | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space for local-track units, attached also capped at 50% of the home and any local-track unit at 10% lot coverage, but never below 800 sq ft; state-exempt detached unit 800 sq ft; conversions uncapped; JADU 500 sq ft; detached 18 ft (20 ft with matching roof pitch, 16 ft on a lot with a JADU), attached 25 ft or zone height | Not required | None for state-exempt ADUs, conversions or JADUs; 1 space per new local-track ADU or per bedroom, whichever is less, waived within 1/2 mile walk of public transit and in the other state exemptions | Permitted use |
| Santa Monica | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,200 sq ft (2+ bedrooms) for local-track ADUs; conversions of an existing home and R1 attached additions also capped at 50% of the home (state 800 sq ft floor applies); state-exempt detached 800 sq ft; JADU 500 sq ft; local detached 2 stories or 24 ft, state-exempt detached 16 to 18 ft | Not required | None for any ADU or JADU, and spaces removed or converted for the unit need not be replaced (coastal-zone parcels: the City refers parking questions to the Coastal Commission) | Permitted use |
| Santa Rosa | Allowed | Allowed | 1,200 sq ft of habitable space for a new detached ADU; attached ADUs 50% of the existing home but at least 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); ADUs converted from inside the house 45% of its habitable space (850/1,000 sq ft floor, 1,200 max); state-exempt 800 sq ft detached unit; JADU 500 sq ft; 16 ft one story (18 to 20 ft near major transit or with a matching roof pitch), 25 ft attached, 27 ft two story | Not required | Usually none: 1 space only for a Zoning Code-track ADU over 750 sq ft (not a studio) outside the exemptions; none within 1/2 mile walk of public transit, in a historic district, for units within the existing home or an existing accessory structure, state-exempt 66323 units, JADUs, near car share, where street permits are not offered, or when built with a new home; no replacement for converted or demolished garage parking | Permitted use |
| Santee | Allowed | Allowed | Local-track ADUs 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space, attached also capped at 50% of the existing home; 800 sq ft streamlined (state-exempt) detached or attached unit; conversions existing space + 150 sq ft; JADU 500 sq ft; detached height 16 ft (18 to 20 ft near major transit) | Not required | None for streamlined (state-exempt) units, conversions and JADUs; 1 space per local-track ADU unless within 1/2 mile walking distance of public transit or another state exemption applies | Permitted use |
| Simi Valley | Allowed | Allowed | Detached: 800 sq ft (state-exempt), otherwise 1,000 sq ft on lots up to 8,000 sq ft and 1,200 sq ft on larger lots; attached: 850 sq ft, or 50% of the home up to 1,000 sq ft if larger; JADU 500 sq ft; conversions uncapped; detached one story and 18 ft, attached 25 ft | Not required | None for state-exempt ADUs and JADUs; 1 space for a local-track ADU unless exempt (studio, within a half-mile walk of public transit, inside the home's footprint, garage conversion, built with a new home, and more) | Permitted use |
| Sonoma County | Allowed | Allowed | 1,200 sq ft on single-family lots (interior floor area; conversions of existing space may exceed it); no cap on multifamily lots; JADU 500 sq ft; height 35 ft; Coastal Zone second units 840 sq ft (1,000 if deed-restricted affordable), 16 ft detached | Not required | None inland (no ADU or JADU parking, no replacement parking); Coastal Zone second units: 1 off-street space unless a Gov. Code 66322 exemption applies | Permitted use |
| South Gate | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); attached the lesser of that or 50% of the home (800 sq ft state floor); 800 sq ft state-exempt detached unit; JADU 500 sq ft; detached height 16 ft | Not required | 1 space per ADU unless exempt (none within 1/2 mile walking of public transit, for units inside the home or an accessory structure, or for JADUs); converted or demolished garage spaces need no replacement | Permitted use |
| Stockton | Allowed | Allowed | 1,200 sq ft detached; attached up to 50% of the existing home or 850 sq ft, whichever is greater (at least 1,000 sq ft with 2+ bedrooms under state law); conversions of existing space not size-capped; JADU 500 sq ft; detached 16 ft (one story) or 25 ft (two stories) | Not required | None (no off-street parking for ADUs or JADUs; no replacement parking when a garage, carport or covered parking structure is removed) | Permitted use |
| Sunnyvale | Allowed | Allowed | 1,000 sq ft for new construction on single-family lots (attached or detached; gross floor area measured from outside walls); no local cap for conversions or for detached ADUs on multifamily lots; JADUs 500 sq ft; height 16 ft detached (18 ft near major transit or on multistory multifamily lots, plus 2 ft for a matching roof pitch), 25 ft attached | Not required | None | Permitted use |
| Temecula | Allowed | Allowed | Detached 1,200 sq ft; attached 50% of the existing house (1,200 sq ft with a new house) but never under 850 sq ft (1,000 sq ft with 2+ bedrooms); state-exempt detached unit 800 sq ft; conversions uncapped (150 sq ft expansion); JADU 500 sq ft; height 16 ft detached (18-20 ft near major transit), 25 ft attached | Not required | 1 space for a new detached ADU built under local standards (tandem on the driveway OK) unless within 1/2 mile walk of public transit or another exemption; none for state-exempt units (including the 800 sq ft detached unit), attached or converted ADUs and JADUs; no replacement parking | Permitted use |
| Thousand Oaks | Allowed | Allowed | 1,000 sq ft detached; attached 850 sq ft or 50% of the home, whichever is greater (state floor 1,000 sq ft for 2+ bedrooms); state-exempt detached 800 sq ft; conversions uncapped; JADU 500 sq ft; 16 ft detached (18 ft near major transit), 25 ft attached | Not required | 1 space for a local-standards ADU with a bedroom over 500 sq ft unless exempt; none for conversions, state-exempt (66323) units, studios, JADUs, or within 1/2 mile of transit | Permitted use |
| Torrance | Allowed | Allowed | 1,000 sq ft attached or detached; 800 sq ft state-exempt detached unit; JADU 500 sq ft; accessory-structure conversions uncapped (plus 150 sq ft for access); detached height 18 ft (1 story) or 23 ft (2 stories) citywide, 16 ft and 1 story in the Hillside Overlay and Coastal Zone; attached 18 ft (1 story) or 25 ft (2 stories) | Not required | 1 space per ADU (uncovered or tandem on the driveway allowed) unless exempt: within 1/2 mile walking distance of public transit (any fixed-route bus stop), in a historic district, within the house or an accessory structure, in a permit-parking area, car share within 1 block, or filed with a new home; none for JADUs or state-exempt units; no replacement for converted or demolished garages | Permitted use |
| Union City | Allowed | Allowed | 1,200 sq ft detached, 1,000 sq ft attached (new floor area); conversions of existing space uncapped; JADU 500 sq ft; detached 16 ft (18 ft near transit or beside a multistory multifamily building, plus 2 ft for a matching roof pitch) | Not required | None (no replacement parking when a garage or space is converted or demolished; none for JADUs) | Permitted use |
| Upland | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms) of interior livable space for locally regulated (Class 2) ADUs; attached also 50% of the home, never below 800 sq ft; 800 sq ft state-exempt detached; conversions uncapped; JADU 500 sq ft; detached 16 ft | Not required | None for state-exempt (Class 1) units, conversions and JADUs; one space per locally regulated (Class 2) ADU or per bedroom, whichever is less, unless a state exemption applies; no replacement parking | Permitted use |
| Vallejo | Allowed | Allowed | Detached 1,200 sq ft; attached the lesser of 50% of the house or 850 sq ft (1,000 sq ft with 2+ bedrooms), never below the state 800 sq ft floor; conversions uncapped; JADU 500 sq ft; height 16 ft detached (18 ft near major transit), 25 ft attached | Not required | One space per ADU over 500 sq ft unless exempt (transit within 1/2 mile, historic district, conversion, permit-parking street, car share, state-exempt 66323 units); none for JADUs; tandem allowed; no replacement parking | Permitted use |
| Ventura | Allowed | Allowed | 850 sq ft studio or 1-bedroom, 1,200 sq ft with 2+ bedrooms (1,000 sq ft in the certified coastal-zone text); attached additions also capped at 50% of the home but never below 800 sq ft; 800 sq ft state-exempt detached unit; conversions uncapped; JADU 500 sq ft; detached 18 ft (20 ft to match roof pitch), one story for local-standards units; attached 25 ft, two stories | Not required | None, except 1 space per ADU or JADU (plus replacement of any displaced garage, carport or open space) in the two coastal-zone ADU Mandatory Parking Areas (Downtown and Pierpont) | Permitted use |
| Ventura County | Allowed | Allowed | 850 sq ft (studio or 1 bed) or 1,000 sq ft (2+ beds) on lots up to 9,000 sq ft; 1,200 sq ft on lots over 9,000 sq ft and under 10 acres; 1,800 sq ft on 10+ acres; conversions uncapped; JADU 500 sq ft; detached height 16 ft; Coastal Zone certified text 700 sq ft | Not required | None for JADUs, studios, conversions and building-permit ADUs (including a detached unit up to 850 sq ft); otherwise 1 space per ADU unless within 1/2 mile walking distance of transit or another state exemption applies; no garage replacement | Permitted use |
| Victorville | Allowed | Allowed | 850 sq ft (studio or one bedroom) or 1,000 sq ft (more than one bedroom), attached or detached; JADU 500 sq ft; height 16 ft detached (18 ft with a roof pitch matching the house), 25 ft attached | Not required | None for ADUs or JADUs (citywide) | Permitted use |
| Visalia | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,200 sq ft (2+ bedrooms), attached or detached; attached also 50% of the house, but state law guarantees 800 sq ft of interior livable space; detached limited to 800 sq ft when paired with a JADU; conversions uncapped (+150 sq ft for access); JADU 500 sq ft; height 16 ft detached (18 ft near major transit +2 ft for roof pitch, 18 ft beside multistory multifamily), attached 25 ft or zone limit, 2 stories | Not required | 1 space per new attached or detached ADU (tandem, or uncovered in setbacks, allowed) unless within 1/2 mile of public transit (any fixed-route bus stop), in the Historic Preservation District or on a local-register property, in a permit-parking area, within 1 block of car share, or filed with a new home; none for conversions or JADUs; no garage replacement | Permitted use |
| Vista | Allowed | Allowed | 850 sq ft (studio or 1 bedroom) or 1,200 sq ft (2 or 3 bedrooms, 3 max), attached also capped at 50% of the home (state 800 sq ft floor); conversions of existing space uncapped; JADU 500 sq ft; one story, 16 ft (state floors: 25 ft attached, 18 ft near major transit) | Not required | 1 space per ADU (covered or uncovered, tandem OK) unless exempt: within 1/2 mile walk of public transit, conversions within the home or an accessory building, historic district, permit-parking areas, car share; none for JADUs; state law bars it for studios and 66323 state-exempt units and bars replacement parking | Permitted use |
| West Covina | Allowed | Allowed | 1,200 sq ft detached; attached the greater of 850 sq ft (0-1 bedroom) / 1,000 sq ft (2+ bedrooms) or 50% of the home up to 1,200 sq ft; conversions uncapped; JADU 500 sq ft; 16 ft height (18 ft near major transit, 25 ft attached) | Not required | 1 space per ADU with a bedroom (none for studios), waived within 1/2 mile walking distance of public transit and the other state exemptions; none for JADUs, ADUs within the home or an accessory structure, or replaced garages | Permitted use |
| Westminster | Allowed | Allowed | 1,200 sq ft detached; attached 50% of the home's living area up to 1,200 sq ft, never below 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); conversions uncapped; 800 sq ft state-exempt detached unit; JADU 500 sq ft; height 16 ft detached (18 ft near major transit), 25 ft attached | Not required | 1 space per ADU with a bedroom (none for studios) unless within 1/2 mile walking distance of public transit or another state exemption; none for conversions, JADUs or state-exempt units; lost garage spaces need not be replaced | Permitted use |
Summarized from each city's ordinance text, most recently read October 2026. Tap a value marked with an info icon to see exactly what it depends on, straight from the ordinance. Nearly every value has zone, lot-size, or process caveats beyond that; the per-city pages carry the full notes and code citations. Treat this as orientation, not a permit determination.
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Reading the table
- Detached ADU is the make-or-break column for backyard cottages: minimum lot sizes (often 8,000 to 14,500 sq ft) hide behind many of the "Allowed" values, so check your lot before celebrating.
- Attached / internal (basement apartments, additions) is legal almost everywhere and is usually the path of least resistance.
- Approval: "Permitted use" means staff-level sign-off; "Conditional use" means a public hearing, which adds time, cost, and uncertainty.
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