Compare ADU zoning rules across 38 California cities. Average ADU score: 7.3/10.
Gathered from the 38 cities below, with the bill or ordinance each one names. Statewide measures are listed once with the cities they reached, rather than repeated for each.
Statewide law sets a floor; the numbers that decide your project are local. Here is the spread across the 38 California cities covered here, taken from each city's own ordinance rather than a state summary.
| Question | Across California |
|---|---|
| Are ADUs permitted? | 38 of 38 permit them. |
| Detached size cap | Median 800 sq ft, from 220 to 1,400 sq ft across the 38 cities publishing a numeric cap. |
| Owner-occupancy | Required in none of them. |
| Build cost | $150,000 to $550,000 depending on city and unit type. |
| Easiest and hardest here | Berkeley scores 9/10; Huntington Beach scores 4/10. |
Recomputed whenever a city page changes, so this and the city pages below cannot disagree.
| City | Max Size | Setbacks | Permit Fees | Build Cost | 1BR Rent | Score |
|---|---|---|---|---|---|---|
| Anaheim | 1,200 sq ft of habitable area (Table 38-A), subject to AMC 18.04.080.020: all detached accessory structures on the lot combined may not exceed the main house's floor area or the zone's minimum livable floor area (1,700 sq ft in RH-1, RH-2, RH-3 and RS-1; 1,225 sq ft in RS-2, RS-3 and RS-4; required garage space not counted). An 800 sq ft ADU with 4-ft side and rear setbacks must be allowed regardless (Gov. Code 66321(b)). Minimum unit size 150 sq ft | 4 ft for any ADU (Table 38-A); a JADU follows the underlying zone. Converting a legally permitted structure needs no setback, and a legal accessory structure may be demolished and rebuilt as an ADU in the same location and dimensions without new setbacks (18.38.015.140). Eaves and roof overhangs must stay at least 12 inches from the property line | Building Permit Fees schedule (Exhibit A, Tier 3 Type VB, Residential Category 1, Dwellings and Custom; posted Aug 2026): combined plan check and building permit of $1,677 for the first 500 sq ft plus $213 per extra 100 sq ft up to 1,000 sq ft (about $2,316 for an 800 sq ft ADU), then $2,741 at 1,001 sq ft plus $171 per 100 sq ft (about $3,083 for 1,200 sq ft). Add trade permits (electrical $26 for the first 100 sq ft plus $0.26 per sq ft; plumbing $49 per fixture; $188 minimum per trade permit), Zoning Plan Check $352 and a $114 address fee (Planning fee schedule, Aug 2025). Budget roughly $3,000-$4,500 in city fees for an 800-1,200 sq ft detached ADU before impact and school fees | $220,000-$450,000 | $2,000-$2,700/mo | 7/10 |
| Berkeley | 1,200 sq ft outside the Hillside Overlay; 850 sq ft (studio/1-bedroom) or 1,000 sq ft (2+ bedrooms) within the Hillside Overlay | 4 ft minimum | $250 zoning plan check + $500 neighbor noticing fee at submittal + $250 address assignment; building permit fees based on project valuation (city fee estimator tool available) | $250,000-$500,000 | $2,300-$2,900/mo | 9/10 |
| Burbank | 850 sq ft for a studio or one-bedroom; 1,000 sq ft with two or more bedrooms (BMC 10-1-620.3(F)(2)); 800 sq ft in the Mountain Fire Zone or when built in the front setback. One ADU per lot may add up to 120 sq ft per extra code-compliant on-site parking space, with a recorded deed restriction (F)(9). Any space over 12 ft in interior height, and attics over 5 ft, count double toward the cap | 4 ft, including an ADU above a garage (10-1-620.3(H)(1)); a legally permitted garage or accessory structure converted in place keeps its existing setback, with 4 ft applying to any added footprint (H)(3). Balconies or patios more than 7 in. above grade and second-story stairs also need 4 ft | Planning ADU application fee $1,728.42 (FY2026-27 Planning Fees, effective July 1, 2026); building plan check and permit fees are valuation-based under the Citywide Fee Schedule (confirm with Building & Safety, (818) 238-5220). BWP water charges run 'from a few hundred up to ten thousand dollars' depending on fixture count, main location and any new service, paid before Water Division approval; BWP electric aid-in-construction fees and a kVA capacity charge apply to any new, upgraded or relocated panel (since Oct 1, 2023). A school district facilities receipt is required at submittal | $220,000-$400,000 | $2,100-$2,600/mo (Zumper Sept 2026 $2,137; RentCafe Aug 2026 $2,598 apartment averages) | 6/10 |
| Carlsbad | 1,200 sq ft on a single-family lot; detached ADUs over 800 sq ft must also fit the zone's lot-coverage limit (IB-111, Aug. 2026). Mandatory-approval detached ADUs of 800 sq ft or less get 4-ft setbacks and may encroach into the front setback if nothing else fits (CMC 21.10.030.E). | 4 feet minimum for attached and detached ADUs (IB-111; CMC 21.10.030). A converted non-conforming garage or accessory structure may keep its existing setback, except in the Coastal Zone where it affects a geologic setback, view, access or habitat buffer. | About $2,800-$3,000 permit plus plan check for a 750-1,200 sq ft ADU: R-3 base fee $1,700 up to 1,000 sq ft plus $0.35 per extra sq ft, plan check 65% of the permit (FY 2026-27 Master Fee Schedule, eff. Sept. 1, 2026); the city's ADU page says $2,000-$4,000. Coastal Zone detached: $3,974 minor CDP. | $300,000-$450,000 | $2,700-$3,350/mo | 7/10 |
| Chula Vista | 1,200 sq ft of floor area (Gov. Code 66314(d)(5), which the city applies directly; city ADU page). A detached ADU of up to 800 sq ft with 4 ft side and rear setbacks and 16 ft height cannot be blocked by lot coverage, floor-area-ratio or open-space limits (Gov. Code 66321(b)(3)). | 4 ft minimum for new construction; none for a conversion of an existing structure or a rebuild in the same footprint (Gov. Code 66314(d)(7)). The city imposes no minimum separation from the main house; the Building Division applies fire-rated wall rules instead (city ADU page). | Fee Bulletin 10-400 (Sept 2024): detached ADU on a City Standard Plan $3,951 (intake $476 + plan check $533 + inspection $2,942); custom detached up to 1,200 sq ft $4,963; garage conversion $1,604 for the first 400 sq ft. Fire, school and utility fees are extra. | $300,000-$450,000 | $2,300-$3,700/mo | 8/10 |
| Citrus Heights | Local option: 1,200 sq ft regardless of the primary home's size (§106.42.015.B.3.b), measured as interior livable space from the inside face of the exterior walls, excluding garages, porches and unfinished space (E.4). Above 800 sq ft the zone's lot coverage applies: 30% in RD-1 to RD-4, 50% in RD-5 to RD-15 (Table 2-4). State option: 800 sq ft (§106.42.015.C.1.a(3); Gov. Code §66323(a)(2)). No local standard may block an 800 sq ft unit with 4-ft side and rear setbacks (Gov. Code §66321(b)(3)). | 4 ft for a newly built ADU (§106.42.015.E.1); none for converting, or rebuilding in place, an existing structure (E.1.a). The city's ADU web page and FAQ, written before the 2026 rewrite, still show a 20-ft rear yard for attached ADUs (reducible to 10 ft); the adopted code and Gov. Code §66314(d)(7) cap side and rear setbacks at 4 ft for any new ADU, so ask Planning at (916) 727-4740 before designing to 20 ft. No ADU may sit in an easement without the holder's written consent (E.1.b). | Valuation-based (Master Fee Schedule, February 1, 2026): a $200,000 ADU pays about $2,933 building permit plus 65% plan check ($1,906), 6% General Plan and 4% technology surcharges, a 3.25% zone check and $94 issuance, roughly $5,300 in all; get a quote from Building at (916) 727-4760. | $170,000-$400,000 | $1,700-$1,950/mo | 8/10 |
| Corona | 1,200 sq ft (CMC 17.85.040(D)). The ADU plus the main house must also stay within the zone's lot-coverage limit, but no standard may block an ADU of at least 800 sq ft and 16 ft in height (17.85.040(E)). An ADU built inside existing space of the house or an accessory building has no size cap. | 4 ft maximum for a new attached or detached ADU, including lot lines along a street (CMC 17.85.040(F)(2)); none for conversions of existing living area or accessory structures, or for a rebuild in the same location and dimensions (F)(1). The city's ADU guide sheet also asks for 5 ft between an ADU and the main house or other accessory buildings. | $2,466 for a garage-to-ADU conversion (plan check $1,383.61 + inspection $1,082.60; $2,684 from Oct 4, 2026 under Res. 2026-085) and up; a new ADU is priced per sq ft as new single-family construction (Table A: $3,611 at 2,000 sq ft, Type V-B) plus 5% General Plan maintenance. | $180,000-$320,000 | $1,800-$2,150/mo | 6/10 |
| El Cajon | 1,200 sq ft of habitable space; ordinance also said the ADU may not exceed the primary dwelling's size — a provision HCD flagged as noncompliant, so confirm with Community Development | 4 ft minimum (3 ft allowed at 12 ft height; 5 ft required for 20 ft height) | Roughly $12-$14 per sq ft in permit costs (local builder estimate); total permitting typically $9,000-$20,000 — confirm current schedule with El Cajon Building & Fire Safety | $300,000-$450,000 | $1,800-$2,100/mo | 6/10 |
| Elk Grove | 1,200 sq ft (EGMC 23.90.040(F)(2)); minimum 150 sq ft (23.90.040(E)). A conversion of an existing accessory structure may expand up to 150 sq ft for entry and exit (23.90.040(D)(1)). | 4 ft for new construction (EGMC 23.90.040(G)(2)); none for a conversion of existing living space or an accessory structure, or a rebuild in the same location and dimensions (23.90.040(G)(1)). | The Building Division charges a set fee per ADU for plan review, inspections and administrative time (OTC handout B-04-10) and did not publish the 2026 amount on a page readable on 9/20; ask a permit technician at (916) 478-2235 for a written estimate before you design. | $170,000-$400,000 | $1,900-$2,500/mo | 8/10 |
| Escondido | 1,200 sq ft of interior livable space for a Standard ADU (Section 33-1475(d)(2)); a State Exempt detached ADU is capped at 800 sq ft (Section 33-1474(b)(2)). A Standard ADU of 800-1,200 sq ft must meet the zone's front setback and lot coverage; one under 800 sq ft is exempt from both (Section 33-1475(e)(1), (f)). An attached patio cover or similar structure may not exceed 49% of the ADU's area. | 4 ft minimum for detached ADUs and new attached ADUs (Sections 33-1474(b)(1), 33-1475(e)(2)); none for an existing structure converted or rebuilt to the same footprint. Eaves, sills and similar features may project up to 4 ft into a rear setback but no closer than 3 ft to the lot line (Section 33-1475(e)(3)(B)). | Permit fees follow the room-addition method: valuation of $226.08 per sq ft, permit fee from Table 3-A, plan check at 75% of it plus state surcharges, about $6,100 for an 800 sq ft ADU and $7,300 for 1,000 sq ft (Fee Guide updated Sept. 16, 2025); school fees are extra. | $300,000-$450,000 | $2,070-$2,320/mo | 7/10 |
| Folsom | 1,000 sq ft with 2 or more bedrooms, 850 sq ft with 1 bedroom or fewer, measured as interior living space, minimum 150 sq ft (FMC 17.105.150(B)(2)). A new detached unit of 800 sq ft or less with 4-ft setbacks is a '66323 unit' exempt from design review, and no standard may preclude an 800 sq ft ADU (17.105.150(C)(2)). Detached ADUs on two-unit and multi-unit lots are capped at 800 sq ft (17.105.170(B)(2)). | 4 ft minimum (FMC 17.105.150(B)(3)); the city recommends 5 ft to avoid extra Fire Code construction requirements. No setback change for a conversion of an existing house or accessory building, or for an ADU built on top of an existing accessory building that already sits closer than 4 ft. | Flat building permit fee of $4,852 per detached or attached ADU and $2,329 per JADU, covering plan review and inspections (Res. 11481, effective July 1, 2026), plus an $81 processing fee and state surcharges; design review for a non-66323 unit adds $400 (Director level). | $170,000-$400,000 | $1,650-$2,400/mo | 7/10 |
| Fontana | 1,200 sq ft for a Class 2 (locally regulated) detached ADU; 800 sq ft for a Class 1 detached ADU, which gets only the state minimum standards (no design review, no parking). On a multifamily lot each detached ADU is capped at 850 sq ft, or 1,000 sq ft with more than one bedroom (ADU Information Sheet, March 2026; Sec. 30-467). | 4 ft minimum for new construction (Sec. 30-467; ADU Information Sheet, March 2026). Conversions of existing structures and their same-footprint rebuilds keep the existing setback (Gov. Code 66314). | No flat ADU fee: building permit and plan check are valuation-based per the Comprehensive Fee Schedule (Res. 2024-054, 9/1/2024), plus Planning plan check $191, Engineering $120 and Fire $90 per submittal and small state/archive add-ons. Get a quote from Building & Safety, (909) 350-7640. | $175,000-$320,000 | $1,750-$1,900/mo | 8/10 |
| Fremont | 1,200 sq ft of interior livable space for a new detached ADU (FMC 18.190.005(c)(4)(B)(ii)); garages, carports, covered porches, patios and breezeways are not counted. An ADU converted from existing floor area has no size limit (c)(4)(A). Rooftop decks are prohibited (c)(4)(C). | 4 ft for an ADU built from new floor area (FMC 18.190.005(c)(6)(B)). None for an ADU within existing living area or an existing accessory structure, or one that replaces a structure in the same location and dimensions; up to 150 sq ft may be added for ingress and egress, and any larger expansion is held to the new-construction setbacks and height (c)(6)(A). | Limited Design Review for an ADU/JADU: $2,000 deposit billed at cost. Building plan check and inspection are valuation-based (e.g. $967.27 + $5.91 per $1,000 above $100,000) plus 15% Community Planning and 3% technology surcharges (Master Fee Schedule eff. 7/1/2026); preapproved plans $1,000 flat. | $250,000-$460,000 | $2,600-$3,000/mo | 8/10 |
| Fresno | The greater of 1,400 sq ft or 50% of the average floor area of the primary unit(s) (FMC 15-2754.D.4.a). A conversion of an existing accessory structure may expand up to 150 sq ft beyond its footprint for ingress and egress (D.4.a.i). ADUs are excluded from lot-coverage and density calculations (D.1, D.2). | The underlying district's rear setback or 4 ft, whichever is less (FMC 15-2754.D.6.a). 0 ft where the lot abuts an alley, or 2 ft if the ADU's main entrance faces the alley (D.6.a.i). A recorded utility easement must stay clear even if that forces a larger setback (D.6). | Pre-approved plans: plans and plan check free; the city's Oct 2025 estimator puts the building permit at $2,344-$2,861 by plan. Custom ADU: Master Fee Schedule (eff. 7/1/2026) R-3 Custom = $599.56 plan check + $1,946.03 inspection at 1,000 sq ft, plus a 12.83% General Plan surcharge. | $150,000-$320,000 | $1,300-$1,550/mo | 8/10 |
| Glendale | 1,000 sq ft maximum: 850 sq ft with one bedroom, and any ADU over 850 sq ft must have a second bedroom. An ADU of 800 sq ft or less is the state-protected size (4-ft side and rear setbacks, no floor-area-ratio or lot-coverage test); over 800 sq ft the zone's FAR, lot coverage and landscaping standards apply (GMC 30.34.080; city ADU page, Nov. 7, 2025). | 4 ft from interior (side and rear) property lines for an ADU of 800 sq ft or less; no setback for a conversion of an existing permitted structure or a rebuild in the same footprint (GMC 30.34.080; Gov. Code 66323(a)(2)). Larger ADUs follow the zone's setbacks, but state law caps what the city may require at 4 ft for side and rear (Gov. Code 66321). | Glendale publishes no flat ADU permit fee: plan check and building permit fees are valuation-based, so request an estimate from the Building Division, (818) 548-3200. The city's development impact fee is about $5,000 and is waived for ADUs of 750 sq ft or less. | $175,000-$375,000 | $2,000-$2,700/mo | 6/10 |
| Hayward | 1,200 sq ft of interior livable space for a newly built detached ADU (SFR/MFR checklists, April 2026, item 5/6); no size limit for conversions of existing, permitted structures; state law guarantees at least 850 sq ft (studio/1BR) or 1,000 sq ft (2+BR) (Gov. Code 66321(b)) | 4 ft for a newly built ADU; none for conversions of existing, permitted structures (SFR checklist item 4) | Planning's ADU Zoning Conformance Permit is a $498 fixed fee (FY2026-27 Master Fee Schedule, eff. July 1, 2026); building permit fees are valuation-based (about $2,917 inspection fee on $250,000 plus plan-check, review and issuance multipliers of about 2.3x) plus $158 housing review and $340 address | $200,000-$425,000 | $2,000-$2,500/mo | 7/10 |
| Huntington Beach | 1,200 sq ft under state law (Gov. Code 66314(b)(5)); the city cannot apply a lot-coverage, floor-area or open-space rule that would keep out an 800 sq ft detached ADU with 4-ft side and rear setbacks (Gov. Code 66321(b)(2)). The city's free pre-approved plan is a 490 sq ft one-bedroom, one-bath detached unit with an optional 53 sq ft porch | No more than 4 ft for a new detached or attached ADU (Gov. Code 66321(b)(3), 66323(a)(1)); no setback for converting an existing legal structure or rebuilding one in the same footprint and dimensions (Gov. Code 66314(b)(7)). Coastal-zone projects may be held to specific-plan setbacks where they exceed 4 ft (a 2026 downtown project used 5 ft interior and 10 ft street-side) | $40 processing plus an inspection fee set by city valuation (about $1,664 at $150,000), 61% building and 46% planning plan review, trade permits, and a 6% automation fee (Res. 2023-21); roughly $4,000-$6,000 for a 490-800 sq ft ADU. A Coastal Development Permit adds $5,756 (single-family lot) | $185,000-$420,000 | $2,600-$2,800/mo | 4/10 |
| Irvine | 1,200 sq ft (Gov. Code 66314(d)(5)). An 800 sq ft unit with 4-ft side and rear setbacks must be allowed regardless of lot coverage, floor-area ratio or lot size (66321(b)(3)); the city's checklist (Form 67-01, rev. 1/25) states the same 1,200 and 800 sq ft figures | 4 ft (66314(d)(7)); none for a conversion of existing space or a rebuild in the same footprint | Planning ADU review is hourly at $217.64 against a $1,500 deposit; building plan check plus inspection is $0.68 + $0.56 per sq ft for a new detached unit ($0.86 + $1.33 for additions and conversions) plus 10% automation fee (Aug 15, 2026 schedules); roughly $2,700-$3,900 all-in for a 750 sq ft ADU | $185,000-$420,000 | $3,100-$3,700/mo | 6/10 |
| Long Beach | 800 sq ft for a new detached ADU on a single-family lot (IB-PZ-001 Table 1, applying Gov. Code 66323(a)(2)(A)); ADU floor area is measured to the interior walls. On a multifamily lot a detached ADU has no size limit. Converting an existing detached garage or accessory building has no size limit either, but the only addition allowed is up to 150 sq ft for stairs or an entry. State law lets a city allow up to 1,200 sq ft (Gov. Code 66314(d)(5)), which the city's February 2025 summary did; if you want more than 800 sq ft on a single-family lot, ask the Planning Bureau (562-570-6194) before designing | 4 ft for new construction, measured to the centerline of the alley where the lot abuts one (IB-PZ-001 Table 3 note b). A converted or rebuilt existing building keeps its existing setback if the Building Official and Fire Code Official find it sufficient for fire and life safety | $5,500-$6,500 in city plan-check and permit fees for a 750-800 sq ft new ADU (derived from the Building Permit & Plan Check Fees effective 5/20/2026 and IB-077's $175.92 per sq ft R-3 valuation): combination building permit at 150% of the valuation-based permit fee ($1,264 for the first $100,000 of valuation plus $6 per $1,000 above, min $164), combination plan check at 85% of the permit fee (min $154), zoning plan check at 0.5% of valuation (min $310), NPDES at $2 per $1,000 plus 75% for plan check, a $115 processing fee per application, and 6% Technology and 6% General Plan surcharges on all applicable fees; expedited plan check costs 2x. The city's own guide: budget about 2% of construction cost for plan check, permits and inspections. Impact, school and sewer fees are extra | $215,000-$400,000 | $1,800-$2,400/mo | 8/10 |
| Los Angeles | 1,200 sq ft under the city ordinance (12.22 A.33(d)(1)), subject to the lot's floor-area (RFA/FAR) and lot-coverage limits; the state-law option (Gov. Code 66323(a)(2)) is 800 sq ft, and no floor-area, lot-coverage, open-space, front-setback or lot-size rule may block an 800 sq ft unit with 4-ft side and rear setbacks (12.22 A.33(c)(1)(iii); Gov. Code 66321(b)(3)). Square footage is measured as Building Code gross floor area inside the exterior walls (ZA Memo 143 Q.3). Conversions of an existing garage or accessory building have no size cap and may add up to 150 sq ft for entry and exit (66323(a)(1)) | 4 ft for a new detached ADU or a new addition (12.22 A.33(c)(8); Gov. Code 66323(a)(2)). None for an ADU created inside an existing house, garage or accessory building, or rebuilt in the same location and dimensions | No flat ADU fee. The LADBS building permit fee is set by construction valuation under LAMC 91.107 Table 1-A: for a valuation between $100,000 and $500,000 the codified base is $395 plus $3.50 per $1,000 (about $1,445 on $300,000, or about $2,384 as a combined building-mechanical permit at 165% of that figure), plus plan check at 90% of the permit fee (91.107.3.1.1), a 2% plan-maintenance fee (91.107.4.3), a fire-hydrant fee of 0.22% of valuation on jobs of $50,000 or more (91.107.4.4), state seismic and green-code surcharges, and the City Planning General Plan Maintenance Surcharge, raised from 7% to 10% on June 9, 2026 (CF 09-0969-S4). Table 1-A amounts are indexed to CPI every July 1 (91.107.1.1), so run the LADBS Permit Fee Calculator for the current total. LAUSD developer fees of $5.38 per sq ft apply to an ADU larger than 500 sq ft from August 11, 2026 (about $4,300 on 800 sq ft) | $220,000-$400,000 | $2,050-$2,550/mo | 9/10 |
| Oakland | 850 sq ft for a studio or one-bedroom unit; 1,000 sq ft for two or more bedrooms, measured as total floor area including all areas within the ADU (Table 17.103.01, Category 2; 7/21/2026 Zoning Criteria Checklist). A Category 1 conversion of an existing detached garage or shed has no size cap other than the existing building envelope plus up to 150 sq ft for an entrance; if enlarged by more than 150 sq ft the whole unit is capped at 850/1,000 sq ft and the addition must meet setbacks (Table notes 3 and 4) | 4 ft from the rear lot line, or the zone's regularly required rear setback if that is smaller, but never less than 3 ft (Table 17.103.01, Category 2). Category 1 conversions and JADUs inside an existing building have no ADU setback, even if the building is nonconforming (note 6). Lot coverage, rear-setback coverage and FAR limits cannot be used to block one JADU plus one ADU of up to 850 sq ft and 18 ft with 4-ft side and rear setbacks | Zoning: ADU Design Review Exemption (Categories I, II and III) $878.58 base, $1,061.45 total with the 7.2% General Plan Update and 12.70% Technology/Records surcharges; ADU Amnesty Program $1,765.74 total (Zoning Fee Schedule FY2026-27, loaded September 4, 2026). Permit application intake $134.32 online or $201.49 at the counter. Building permit (Master Fee Schedule effective July 1, 2026, R-3): new construction plan review $10.60 plus inspection $8.00 per $1,000 of construction value, each with a $335.81 minimum; alterations and additions $17.08 plus $26.11 per $1,000; electrical, plumbing and mechanical inspections $7.66, $4.79 and $4.36 per $1,000 of each trade's value; plus a 7.20% General Plan surcharge and a 12.70% Records Management and Technology fee on building fees; zoning inspection $537.28 on a new-construction residential permit. Our arithmetic for a $300,000 new detached ADU: about $6,700 in building plan-check and inspection fees plus $1,061.45 zoning, before trade permits. The City's own rule of thumb is 4-6% of project value. Separate: new sewer lateral connection permit $1,798.93 (Public Works schedule, expressly including ADUs) and the OUSD school fee of $5.17 per sq ft | $210,000-$400,000 | $2,100-$2,500/mo | 8/10 |
| Oceanside | 1,200 sq ft under the state standard Oceanside now applies (Gov. Code 66314(d)(5)). A unit of at least 850 sq ft (studio/1BR) or 1,000 sq ft (2+ BR) cannot be blocked by lot coverage, floor-area ratio or open-space rules (66321(b)(2)-(3)), and an 800 sq ft detached ADU with 4-ft side and rear setbacks is approved by right regardless of other standards (66323(a)(2)). | 4 ft is the most the city may require for new construction; none for a conversion of an existing structure or a rebuild in the same footprint (Gov. Code 66314(d)(7)). Coastal Zone: the certified LCP's habitat buffers and coastal-bluff geologic setbacks still apply to garage conversions and units built above garages (Coastal Commission certification LCP-6-OCN-18-0055-1, Sept 2018). | No ADU-specific fee figure is published: the 2019 ADU fee schedule was removed from the city ADU page and plan-check and permit fees follow the Building Fee Schedule on the Development Services Fees page (2026). Ask the Building Division for a quote before design. | $300,000-$450,000 | $2,200-$2,700/mo | 7/10 |
| Ontario | 1,000 sq ft of interior livable space for 2 or more bedrooms; 850 sq ft for a studio or 1-bedroom (Dev. Code 5.03.010.F.1.a). Lot coverage (30-60% by zone) can shrink it, but never below 800 sq ft (F.1.c). A state-standard Class 1 detached unit of 800 sq ft or smaller with 4 ft side/rear setbacks is approved without Ontario's design, landscape or front-setback rules (D.3.a(2)). | 4 ft minimum (Dev. Code 5.03.010.F.2.a); no setback for a conversion or for a unit rebuilt in the same location and dimensions as an existing structure (F.2.b). Detached structures must be 6 ft apart (ADU Handout, Rev. 01.21.2025). | Building permit by valuation (Table A: $993.75 plus $5.60 per $1,000 above $100,000), plan check at 80% of the permit fee and an earthquake fee of 0.0001 x valuation: roughly $2,300-$3,600 at a $150,000-$250,000 valuation, before trade permits, DIF and school fees. | $180,000-$320,000 | $2,000-$2,250/mo | 8/10 |
| Pasadena | 1,200 sq ft for a new detached ADU on a single-family lot (17.50.275.D.1.a). Hillside Overlay lots outside HD-1: 1,000 sq ft, or 800 sq ft where the street pavement is 26 ft wide or narrower (D.1.b). Conversions of existing space have no size limit. Floor area may be measured by the Zoning Code or the California Building Code, whichever the applicant prefers (D.1.d). | 4 ft for new construction and for any addition to a conversion ADU. No setback beyond fire-safety needs for a conversion of existing space or for a rebuild in the same location, dimensions and height (17.50.275.D.3.a). | Valuation-based (FY2027 General Fee Schedule, adopted June 8, 2026): building permit $1,738 plus $6 per $1,000 over $100,000; plan check $2,607 plus $9 per $1,000; Construction Tax 1.92%; General Plan and Technology fees 0.5% each; refundable C&D deposit flat $1,000; new address $345. | $150,000-$400,000 | $2,300-$3,000/mo | 7/10 |
| Rancho Cordova | 850 sq ft for a studio or one-bedroom; 1,000 sq ft with two or more bedrooms (city ADU standards table, RCMC 23.901.060). Those are exactly the floors a city must allow under Gov. Code 66321(b)(2): the published cap is the state minimum, the city publishes no higher figure (such as 1,200 sq ft), and the codified text could not be read. Lot coverage cannot block an 800 sq ft unit with 4 ft side and rear setbacks (66321(b)(3)); a detached unit under the 66323 route is capped at 800 sq ft. | 4 ft (city ADU standards table), the most state law allows for a newly built ADU (Gov. Code 66314(d)(7)). No setback may be required for an existing structure converted to an ADU, or for a new structure rebuilt in the same location and to the same dimensions. The city notes its setbacks are general standards that may vary with existing easements. | No published ADU permit fee. Rancho Cordova gives Building Permit and Development fee estimates on request by email to PermitServices@CityofRanchoCordova.org with the proposed square footage; no fee schedule appears on the ADU FAQ or the Building and Safety pages (checked 2026-09-20). | $170,000-$400,000 | $1,400-$1,800/mo | 7/10 |
| Rancho Cucamonga | 1,200 sq ft maximum, 350 sq ft minimum (Handbook p. 7; RCMC 17.100.050). Lot-coverage limits may cap a detached unit, but never below 800 sq ft at 16 ft height with 4 ft side and rear setbacks (Gov. Code 66321). | 4 ft minimum from the rear lot line for new construction, detached or attached; converting an existing garage or accessory structure keeps its existing setbacks (Handbook pp. 7-9; RCMC 17.100.050). | FY2026-27 Master Fee Schedule (eff. July 1, 2026): ADU building permit $1,822 up to 500 sq ft plus $44 per additional 100 sq ft (about $1,954 at 800 sq ft, $2,130 at 1,200 sq ft), plus 12% technology and 10% General Plan fees and a $343 processing fee; $1,363 with a pre-approved plan. | $175,000-$350,000 | $2,150-$2,300/mo | 8/10 |
| Riverside | 1,200 sq ft of floor area (RMC 19.442.030(D)(2)). A movable ADU (MADU, a unit on a chassis) must be 150-430 sq ft measured to the outside of the exterior walls (D)(3). Any ADU must be at least the size of an efficiency dwelling unit under California Building Code 1208.4 (D)(5). ADU floor area is not counted toward lot coverage (A)(8) | 4 ft for a new one-story ADU or MADU up to 16 ft tall, measured from the rear lot line and from other buildings; a taller or two-story new ADU, or a new second story added to an existing structure, must meet the base zone's rear setback (RMC 19.442.030(C); city ADU FAQ). No added setback for converting an existing structure or an existing second story. State law caps side and rear setbacks at 4 ft for any new ADU (Gov. Code 66314(d)(7)) and guarantees a detached ADU of at least 800 sq ft with 4-ft setbacks at 16 ft (18 ft near major transit), so ask the Planning Division before assuming a larger setback applies to a taller unit | Valuation-based, not flat: roughly $1,400-$1,500 in Building & Safety permit and plan-check fees for an 800 sq ft ADU on the FY2023-24 schedule ($100.04/sq ft valuation), plus Planning's $289 zoning check and surcharges; the city's 2022 workshop put all-in fees at $3,000-$9,000. | $180,000-$320,000 | $1,750-$1,950/mo | 8/10 |
| Roseville | 850 sq ft (studio/1BR) or 1,000 sq ft (2+BR) per city handout — the state floor; minimum 150 sq ft | 4 ft for new construction; none for conversions of existing structures (including same-footprint rebuilds) | Per the city's Accessory Dwelling Units Fee Policy — confirm current amounts with Development Services at (916) 774-5332 | $170,000-$400,000 | $2,050-$2,350/mo | 6/10 |
| Sacramento | Local option: 1,200 sq ft for one detached ADU; with two detached ADUs their combined floor area may not exceed 1,200 sq ft, for example 400 + 800 (17.228.105(B)(2)(b)(iii)). Floor area counts everything inside the ADU's building envelope except garages and accessory structures. State option: 800 sq ft for a new detached unit (17.228.105(C)(1)(b)) | 3 ft or none under the local option: no rear setback is required for a single-story ADU, or the first floor of a two-story ADU, when the whole unit is more than 60 ft from the front property line; if any part is within 60 ft of the front property line, or for a second floor, the zone's rear setback or 3 ft applies, whichever is less, so 3 ft in R-1 and R-2 (17.228.105(B)(2)(c)(iii)). No setback for an existing structure converted or rebuilt to the same footprint. No ADU may sit inside the 20-ft setback from the landside toe of a levee (17.204.240(E)). State option: 4 ft (17.228.105(C)) | City fee estimate form CDD-0419 (rev. 7/12/2026), at a $170.80 per sq ft valuation: about $5,272 total for a 749 sq ft new detached ADU, $10,624 at 750 sq ft and $14,843 at 1,200 sq ft. Line items at 1,200 sq ft: building permit $1,790.36, plan review $751.95, fire administrative $176, fire inspection $294 ($0.11 per sq ft, $294 minimum), fire plan review $260, planning inspection $526, planning review $263, public works and utilities review $205 deposit each plus hourly, construction excise tax $945.60, general plan fee $533 ($2.60 per $1,000 of valuation), residential construction tax $315, technology fee $254.23. Not included: school district fees (paid to the district, form CDD-0226), regional sanitation and county sewer fees, and any water or sewer tap, housing or project-area impact fees. Optional ADU Zoning Review: $0 (was $117 before July 2026). Optional written fee estimate: $164 (form CDD-0278). Extra review time bills at $216 per hour for Building and $263 per hour for Planning | $170,000-$400,000 | $1,500-$1,850/mo | 9/10 |
| San Bernardino | 1,000 sq ft of interior livable space for a unit with two or more bedrooms and 850 sq ft for a studio or one-bedroom under the city's Class 2 standards (19.04.030(2)(P)(7)(a), Ordinance MC-1659); a Class 1 detached ADU under state law is 800 sq ft of livable space or less (5.a.ii). No lot-coverage, FAR, front-setback or open-space rule may force any ADU below 800 sq ft (7.a.iii). Minimum interior width 10 ft in every direction with a 7-ft ceiling (7.h.v) | 4 ft (19.04.030(2)(P)(5)(a)(ii) for a Class 1 detached ADU; 7.c.i for a Class 2 ADU). No setback beyond fire-code separation for a conversion inside existing space, and none when the ADU is built in the same location and to the same dimensions as an existing structure (7.c.ii) | The posted Building & Safety fee schedule (07/2020) has no ADU line, so a new detached unit is priced like a new in-fill dwelling: plan review at the hourly rate of $122.37 (5 hours, about $612, for a new dwelling; 3 hours, about $367, for an addition), a building permit of $1,461 for a unit up to 1,200 sq ft (Table 1B, including electrical, plumbing and mechanical inspections) or $1.92 per sq ft for an attached unit with a bath or kitchen ($375 minimum, $1,459 maximum up to 1,200 sq ft), plus a 2% technology fee and 2% General Plan maintenance fee, a $55 zoning consistency review, $167.40 for the certificate of occupancy when it is on the building permit, state SMIP at 0.0001 x valuation and archive fees of $3.15 per plan sheet; expect roughly $2,300-$2,800 in city plan-check and permit fees for a detached ADU before school, sewer and impact fees. The Planning Division's February 2024 schedule lists no ADU review fee; MC-1659 lets the city set an ADU-permit processing fee by council resolution (4.b), so confirm with Planning. Pre-approved plans are bought from their designer at the designer's price | $150,000-$300,000 | $1,550-$1,800/mo | 7/10 |
| San Diego | 1,200 sq ft gross floor area (minimum 150 sq ft) for a new attached or detached ADU (SDMC 141.0302(b)(7)). ADU floor area counts toward the lot's floor area ratio, but one ADU of 800 sq ft or less is always allowed and is exempt from FAR, lot coverage, front setback and open-space rules (141.0302(b)(4)). Garage or carport space under an ADU and an exterior-access mechanical closet do not count toward the 1,200 sq ft (DSD FAQ) | None for an ADU 16 ft or lower outside a High or Very High Fire Hazard Severity Zone; the Building Code's fire-separation rules may still push the wall off the line. Over 16 ft next to a residential lot: 4 ft or the zone's rear setback, whichever is less. In a High or Very High Fire Hazard Severity Zone: 4 ft at any height (141.0302(b)(9)(C)-(D)). Conversions and same-footprint rebuilds keep the existing structure's setbacks (141.0302(a)(5)) | IB-501 (August 2026), Table 501A: a detached ADU of 500 sq ft or less, or an attached ADU or JADU up to 1,100 sq ft, pays $3,512.92 plan check plus $2,228.29 inspection for the first 500 sq ft ($5,741.21) and $6.98 + $4.46 per sq ft above that (about $9,173 for an 800 sq ft attached unit). A detached ADU over 500 sq ft is billed at the single-dwelling-unit rate: $8,085.26 plan check plus $8,401.90 inspection ($16,487.16 flat up to 3,000 sq ft including attached accessory structures). Every project also pays the $737 General Plan Maintenance Fee, a $12.16 mapping fee, a 2.5-hour DIF-calculation review (about $442 at the $176.84 hourly rate), $529.71 per new address, water/sewer plan check of $176.57 (no meter change) or $353.13 (new meter), and state seismic and building-standards fees. School district fees apply to any ADU of 500 sq ft or more (IB-146). Express plan check costs $793.95 plus 1.5x the regular plan check fee | $250,000-$450,000 | $2,200-$2,700/mo | 9/10 |
| San Francisco | State program: 850 sq ft of gross floor area for a studio or 1-bedroom detached ADU and 1,000 sq ft for 2 or more bedrooms on a lot with a single-family home (Planning Code 207.2(c)(1) and (d)(5)(B); Ordinance 222-25 raised the streamlined cap above the 800 sq ft state floor, effective December 22, 2025). A detached ADU on a lot with an existing multifamily building has no maximum size (Planning Director Bulletin No. 3, June 2026). Local program: the same 850 / 1,000 sq ft caps for the one detached rear-yard ADU (207.1(c)(15)(B)). San Francisco measures gross floor area, not interior livable space | State program: 4 ft from the rear lot line for a new detached or attached ADU; no setback for an ADU within existing living space or an existing accessory structure, or one that replaces an existing structure in the same location and dimensions; for an ADU that is part of new construction the 4 ft applies only to the part outside the buildable area (Planning Code 207.2(d)(7)). Local program: 4 ft for the detached rear-yard ADU (207.1(c)(15)(A)); none for a conversion of existing space; otherwise the district rear yard applies, which is 30% of lot depth in RH, RM-1, RM-2 and RTO districts and 25% in other residential districts (Planning Code 134; ZA Bulletin 5, Sept. 2025), unless the Zoning Administrator waives it for an ADU in an existing building (207.1(g)) | Planning Department building-permit review (Fee Schedule effective August 29, 2025, revised June 15, 2026): new construction $3,502 under $100,000; $3,504 plus 3.855% of cost above $100,000 up to $499,999; $19,226 plus 1.230% above $500,000. Alteration or conversion: $504 under $10,000; $516 plus 5.274% above $10,000; $3,838 plus 3.524% above $50,000; $5,638 plus 3.855% above $100,000; back-check $366. DBI building permit (Building Code Table 1A-A, permits issued on or after July 12, 2026): plan review $1,617 plus $15.60 per $1,000 over $50,000, or $4,011 plus $13.31 per $1,000 over $200,000; permit issuance $677 plus $4.83 per $1,000 over $50,000, or $1,402 plus $4.21 per $1,000 over $200,000; plumbing, electrical, mechanical, Fire, Public Works and Public Health fees are extra (Table 1A-A note 1). SFUSD school facility fee $3.79 per sq ft of added habitable area (2026 Impact Fee Register). Worked example (our calculation, not a published figure): a $300,000 detached ADU pays about $11,214 to Planning plus $5,342 and $1,823 to DBI, roughly $18,400 before trade permits and school fees; DBI says City fees typically run 6-9% of construction cost. Fees are waived for permits that legalize units built without permits before January 1, 2020 | $300,000-$550,000 | $3,000-$4,200/mo | 9/10 |
| San Jose | Two tracks that cannot be mixed. City standards (SJMC 20.80.175 D.1, Table 20-55): 1,000 sq ft on lots up to 9,000 sq ft, 1,200 sq ft on larger lots, and no cap when converting an existing detached accessory structure. State standards (SJMC 20.80.176 / Gov. Code 66323): 800 sq ft. Minimum 150 sq ft on either track. Square footage is livable floor space measured to the exterior finish; a covered porch or balcony more than 50% enclosed counts (20.80.175 E.3). | City standards: 0 ft for a one-story detached ADU; 4 ft, with eaves of 1 ft or less, for any second story (SJMC 20.80.175 D.3). State standards: 4 ft. A structure converted to an ADU keeps its existing setback; Building and Fire Code separations and easements still apply. City-track detached units must sit at least 6 ft from the main home and, with other accessory structures, cover no more than 40% of the rear yard, a cap that cannot block an 800 sq ft ADU with 4 ft setbacks (D.5.c, D.5.e). | FY 2026-27 Building Fee Schedule (effective Aug 10, 2026): ADU 0-750 sq ft $422 issuance + $1,137 plan review + $1,732 inspection = $3,291; 751-1,200 sq ft $633 + $1,950 + $2,520 = $5,103. Excludes construction taxes, school and parkland fees and any planner meeting ($398/hour). | $200,000-$450,000 | $2,500-$3,000/mo | 8/10 |
| San Mateo | No fixed cap: up to the FAR of the underlying zone and no larger than the primary home. The first 800 sq ft of ADU living area is exempt from FAR, and an 800 sq ft state-exempt ADU is always allowed even when the lot's floor area is used up or the main house is under 800 sq ft (SMMC 27.19.060(b)) | 4 ft for new construction; none for a conversion rebuilt to the same footprint and height, or for a detached ADU in the rear third of the lot that meets the R1 accessory-structure rules in SMMC 27.70 (27.19.060(d)) | Flat ADU building permit fees, FY2026-27 Comprehensive Fee Schedule p. 2.5: $2,831.57 new-construction ADU; $2,031.12 ADU remodel/conversion; $1,455.43 eligible manufactured, prefab or pre-approved-plan ADU; $1,454.02 JADU. A detached ADU also pays a wastewater capacity charge of $5.87 per sq ft (Public Works schedule p. 9.5), about $4,700 for 800 sq ft; conversions are exempt (27.19.050(d)). School district developer fees may apply | $300,000-$480,000 | $3,100-$3,400/mo (Zumper Sept 2026 $3,185; RentCafe Aug 2026 $3,406 apartment averages; ADUs typically rent slightly below) | 8/10 |
| Santa Ana | 1,000 sq ft (Table 41-194.3); minimum 220 sq ft. Capped at 800 sq ft when both an ADU and a JADU are built on the same lot (41-194.3(B)). Converting an existing accessory structure or part of the house has no size limit and the structure may be expanded up to 150 sq ft (41-194.3(C)-(D)). An ADU over 800 sq ft must also leave 1,200 sq ft of continuous rear or side open space and sit 15 ft from the main house (41-194.3(I)-(K)) | 4 ft (Table 41-194.3). No setback for a conversion of an existing structure, or for an ADU rebuilt in the same location and to the same dimensions as a demolished structure that already encroached (41-194.3(F)-(G)); an ADU built above an existing garage that encroaches into a required yard must keep 4 ft | Planning Division FY2026-27 fee schedule (effective July 1, 2026): Accessory Dwelling Unit Review $1,940; ADU Over-the-Counter Review $594; ADU Pre-Approved Plan Review $524; Minor Exception (appeal of a denial) $3,579. A 7% technology fee is added to all Planning, Building and Public Works applications, plan checks and permits, and card payments carry a 2.5% processing fee. Building Safety has no ADU-specific line: the FY2026-27 fee schedule (Section X) charges structural plan check and inspection per sq ft by project type, for example $1.42/sq ft plan check for a single-story residential single-family structure ($3.14 two-story) plus $0.81/sq ft inspection, or $1.78 plus $1.42 per sq ft for a first-floor residential addition up to 500 sq ft, with electrical, plumbing and mechanical items priced separately; ask Building Safety at (714) 647-5800 which lines apply to your unit. Public Works: sewer connection fee $53 per plumbing fixture unit and a water capacity fee of $930 for a new 5/8-inch meter (FY2026-27 Public Works summary) | $180,000-$400,000 | $2,250-$2,600/mo | 7/10 |
| Santa Monica | 850 sq ft (studio/1-bedroom) or 1,200 sq ft (2+ bedrooms) under the local standards, 150 sq ft minimum; a garage with an internal connection to the ADU does not count toward the cap (SMMC 9.31.025(I)(1)(c)). The state-mandated alternative under 9.31.025(J) is 800 sq ft | 4 ft (SMMC 9.31.025(I)); no setback for existing space or a structure rebuilt in the same location and to the same dimensions, including unpermitted structures built before Jan 1, 2020 that are converted to an ADU (Guide p.3) | Plan check and building permit fees are valuation-based under the City's adopted fee schedule (finance.smgov.net); Planning charges $985.11 for a deed-restriction application and $833.46 for a Coastal Zone Approval in Concept (fees effective July 1, 2026) | $250,000-$500,000 | $3,000-$3,700/mo | 8/10 |
| Torrance | 1,000 sq ft (800 sq ft under the state-exempt ministerial path); accessory-structure conversions exempt from the cap | 4 ft (detached); same as primary dwelling for attached; none for conversions of existing structures | Fee assessed at building-permit application covering plan review, permit processing, and development impact mitigation — confirm amounts with Community Development, (310) 618-5990 | $200,000-$380,000 | $2,100-$2,400/mo | 5/10 |
| Upland | Building permit only: one detached new ADU of 800 sq ft or less (§ 17.37.040(A)(2)). ADU permit: 850 sq ft for a studio/1-bedroom, 1,000 sq ft for 2+ bedrooms (§ 17.37.060(A)); no lot-coverage, FAR, front-setback or open-space rule may push the ADU below 800 sq ft. | 4 ft minimum (§ 17.37.060(B)); none when the ADU is built in the same location and to the same dimensions as an existing structure | ADU permit fee set by Council resolution (§ 17.37.040(B)); the city's April 2023 guidebook listed $810, plus building permit/plan check typically $3,000-$4,000 and a $189 county fire letter. 2026 amounts not published online; confirm with Building & Safety, (909) 931-4110. | $175,000-$350,000 | $1,900-$2,250/mo | 6/10 |
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