ADUs in Coronado, CA
✓ Verified November 1, 2026 Rules, fees, and timelines below were verified November 1, 2026. Anything marked “confirm” or “to verify” is still open.
Read this first: HCD found this ordinance noncompliant
State HCD itself reviewed Coronado's ordinance and found it noncompliant. HCD's letter (December 10, 2025) reviewed Ordinance No. 2024-02 and found it fails state ADU law on 31 points, with a city response due January 9, 2026. Whether the city has since amended is unconfirmed — the code text still shows the 2022-era citations HCD flagged. Where the code conflicts with state law, state law controls. Confirm current rules with Community Development before designing.
State HCD itself reviewed Coronado's ordinance and found it noncompliant. HCD's letter (December 10, 2025) reviewed Ordinance No. 2024-02 and found it fails state ADU law on 31 points, with a city response due January 9, 2026. Whether the city has since amended is unconfirmed — the code text still shows the 2022-era citations HCD flagged. Where the code conflicts with state law, state law controls. Confirm current rules with Community Development before designing.
Jurisdiction check — read this first.
The entire city is in the Coastal Zone — there is no inland half of Coronado where coastal review drops away.
Coronado Cays and Coronado Shores have their own associations; HOAs cannot outright prohibit ADUs (AB 670) but may impose reasonable design standards — check CC&Rs per parcel, this is not a city rule.
The entire city is in the Coastal Zone — there is no inland half of Coronado where coastal review drops away.
Coronado Cays and Coronado Shores have their own associations; HOAs cannot outright prohibit ADUs (AB 670) but may impose reasonable design standards — check CC&Rs per parcel, this is not a city rule.
Does it apply to my lot? — address check
Enter a San Diego County street address. The checker geocodes it and checks public transit stops nearby. Privacy: your typed address goes directly from your browser to OpenStreetMap's free Nominatim geocoder and the public SanGIS transit-stops layer. It never touches an ADUKey server — ADUKey has no server endpoint for this, so there is nothing to send it to.
Parking-exemption rule: no parking required within a 1/2-mile walking distance of public transit (bus stops included). Straight-line distance is measured first: a straight-line miss is definitive, a straight-line hit is provisional until the walking route is checked.
What you can build
| Rule | What applies | Note |
|---|---|---|
| Detached ADU size | 850 sq ft (studio/1 bedroom) or 1,000 sq ft (2+ bedrooms) | Ordinance text via HCD letter (state agency) + both builder guides agree. Exception (HCD Finding 9): those caps do NOT apply to single-family conversion ADUs, multifamily conversion ADUs, or ADUs detached from a multifamily dwelling — no maximum floor area may be imposed on those three §66323 types. Rejected: GatherADU's 'up to 1,200 sq ft' is generic state-law boilerplate, not Coronado's ordinance. |
| Attached ADU size | Same 850/1,000 sq ft caps; attached ADUs may be two stories within the primary dwelling's height limit | Both builder guides. One older builder page (Better Place, March 2025) adds 'attached ADUs must not exceed 50% of the primary home's square footage' — the 2026 guide does not repeat it. Treat the 50% claim as older-guide-only, to verify; do not publish it as current without a city source. |
| State-exempt ADU (§66323 detached) | Not larger than 800 sq ft, not more than 16 ft high, 4 ft side/rear setbacks — with 18 ft, or 20 ft to match roof pitch, within a half mile walking distance of a major transit stop or high-quality transit corridor | Ordinance via HCD Finding 24 (state agency), with the near-transit correction. |
| Junior ADU (JADU) | 500 sq ft maximum, efficiency kitchen; owner-occupancy required only if the JADU shares sanitation facilities/bathroom with the main house (AB 1154, eff. Jan 1, 2026), with exceptions for governmental agency, land trust, or housing organization owners | HCD Findings 12–16 (state agency). The ordinance's specific appliance list (stove, oven, microwave, refrigerator, sink with garbage disposal) is more restrictive than statute and must be removed. JADU must be within the single-family dwelling, have its own exterior entrance, and have an interior entrance to the main house if it lacks its own bathroom. |
| Height | Detached 16 ft maximum, one story; 18 ft within a half mile of major transit stops or high-quality transit corridors, +2 ft (20 ft total) if roof pitch matches the primary dwelling | Both builder guides + HCD Finding 24. Coronado's ferry terminal meets the statutory definition of a major transit stop (PRC §21155(b), HCD footnote). |
| Setbacks | 4 ft minimum side/rear, or the applicable zone setback, whichever is less | Both builder guides. An ADU using the 4 ft setbacks cannot exceed 16 ft; above 16 ft it must meet underlying zoning setbacks. Front-yard setbacks: state law bars front setbacks from preventing an ADU of at least 800 sq ft. |
| Building separation | 10 ft commonly cited; code-mandated minimum separation unconfirmed — confirm with the city; fire-code material rules may apply under 10 ft | CONFLICTING builder-guide statements, flagged not resolved: Better Place's TL;DR states 'Minimum of 10 feet is required,' but its own setback section states Coronado does not explicitly require a minimum distance; SnapADU's snapshot states 10 feet but its body states the minimum is not applicable, though fire codes may require special materials when closer than 10 ft. Do NOT import the city's SB 9 checklist 10 ft rule — that is a two-unit-development rule, not an ADU rule. |
| Parking | Maximum one parking space per ADU; none for ADUs deed-restricted affordable to low, very low, and extremely low income households. No additional parking required for a JADU. Carriage-house conversions: maximum one space, none if deed-restricted affordable | Ordinance via HCD Findings 17/19 (state agency) + city fact sheet June 5, 2025. Do NOT publish a clean 'no parking within a half mile of transit' rule for Coronado — the ordinance does not state it, and its stated justification for its parking rule is the Coastal Act/LCP, not transit proximity. State parking exceptions are absent from the ordinance and must be added or justified by cited Coastal Act provisions. |
| Parking replacement | Ordinance requires replacement spaces when an ADU/JADU replaces a garage or other required parking; state law bars replacement parking when parking is demolished/converted for an ADU (SB 1211) — publish the conflict | Ordinance via HCD Findings 18/28 (state agency). Any Coastal Act justification must cite specific provisions. |
| Minimum rental term | Ordinance: rentals of six consecutive months or more. HCD correction: state law authorizes a locality to require only a longer-than-30-days limit — the six-month figure must be amended to the 30-day minimum | Ordinance text via HCD Findings 11/15 (state agency); both builder guides repeat the six-month rule. Publish both: the ordinance's six-month text and the HCD correction, with state law controlling where they conflict. |
| Impact fees | Exempt for ADUs at or under 750 sq ft of interior livable space and JADUs at or under 500 sq ft (SB 543, eff. Jan 1, 2026) | Ordinance via HCD Finding 22 (state agency). No Coronado-published ADU fee schedule was found — publish no fee number. Builder-guide estimates of $8–$12/sq ft are not city fees and are not published here. |
| Multifamily lots | Ordinance: up to 2 detached ADUs on a lot with an existing multifamily structure (16 ft max, 4 ft setbacks). State law (SB 1211): up to 8 detached ADUs on a lot with an existing multifamily dwelling, not exceeding the number of existing units; 2 for a proposed multifamily dwelling; conversions of non-habitable space at least 1 and up to 25% of existing units | Ordinance via HCD Finding 25 (state agency) + builder guides. Tension flagged: SnapADU states a 16 ft multifamily height limit, while HCD Finding 25 requires acknowledging height allowances over 16 ft. |
| Overlays to check | Entire city in the Coastal Zone (see section below); no mapped Fire Hazard Severity Zone per CAL FIRE 2025 LRA summary (third-party); flood zones along the shoreline (third-party); homes 75 years old and older reviewed by the Historic Resource Commission before exterior changes (third-party); NASNI ALUCP safety zones per parcel (city fact sheet note) | Third-party summaries unless noted; per-parcel checks required. 'No mapped fire zone' is not 'no fire risk.' Historic-district status for ADU purposes was not researched against a city source. |
Permit path
ADU/JADU application plus building permit application, reviewed by the Community Development Department. Ministerial decision within 60 days of a complete application (ordinance via HCD Finding 27, state agency; both builder guides agree). If the ADU/JADU application is submitted with a new single-family dwelling application, the ordinance delays action until the city acts on the dwelling permit — HCD Finding 27 requires rewording to 'approved or denied' and deciding the ADU/JADU no later than the primary dwelling's approval/denial. Occupancy of the ADU/JADU is barred until the city approves occupancy of the primary dwelling, subject to the §66328 emergency exception. In-person submission only — both builder guides agree Coronado does not accept digital submissions for ADU plans; submissions must be made in person at City Hall. No city-published statement of in-person-only submission was found — to confirm as a city rule, though the builder-guide consensus is unanimous. Builder-guide elapsed timelines (label as such): standard 3–4 months, coastal 4–5 months, approval-to-occupancy typically 4–6 months. Community Development Department, 1825 Strand Way, Coronado, CA 92118; call 619-522-7328, email comdev@coronado.ca.us, or stop by the counter (city-published handout). Do not publish a director name without confirming the current holder (Grunnw per the December 2025 HCD letter vs Jones per a March 2026 staff report).Pre-approved plans — program exists, details unverified
City fact sheet (Housing Element Ordinance Amendments, effective June 5, 2025): 'The City is developing pre-approved ADU plans that homeowners can utilize at no cost beyond standard permitting fees.' No plan sizes, plan count, review track, or availability date stated in that document. A city RFQ for pre-approved detached ADU building permit construction plans (question deadline February 18, 2025) describes downloadable plans free of charge with an expedited permitting process upon submittal of a site plan. A city staff report for the March 25, 2026 Council meeting states, under Program 12 ('Provide pre-approved ADU plans… at varying square footages'): 'Permits were issued for two (2) ADUs utilizing the City's preapproved ADU plans in 2025.' That document's provenance needs verification (it surfaced via search on a shared gov-cloud blob host) before the figure is cited, and it is a partial count, not the city's total 2025 ADU permits. The city's website sitemap lists a 'Pre-Approved ADU Program' page — the program page itself was not opened. Publishable line: pre-approved ADU plans — program in development as of June 2025 (city fact sheet); permits issued for two ADUs using the city's pre-approved plans in 2025 (city staff report, provenance to verify). Plan sizes, count, cost, and 30-day track — to verify.Coastal zone — the whole city, integrated review
The entire City of Coronado is located in the Coastal Zone (HCD Finding 5, footnote 8, state agency; builder guides agree). The city has a certified Local Coastal Program (builder guides state approval in 1983 — confirm against a Coastal Commission source before publishing the year as a Commission fact). No separate CDP application or public hearing specifically for ADUs — coastal review is integrated into standard city permitting (both builder guides; ADU statutes do not supersede the Coastal Act, except the city need not hold public hearings for ADU CDP applications). Ordinance §86.70.120 bars building permits before a coastal permit issues; state law §66329(a) requires CDP and ADU review to happen concurrently unless the applicant requests otherwise (HCD Finding 31). No Coronado-specific appeal-jurisdiction split (city vs Commission) was verified — do not invent one. CDP fee, CDP timeline beyond the builder-guide coastal estimate, and waiver criteria: to verify. Overlays within the coastal zone (builder guide): Beach Overlay Zone street-yard setbacks apply to properties between the ocean and the first public roadway; Coastal Bluff Overlay Zone bluff setback and beach reservation apply.Carriage houses — a Coronado-specific conversion path
City fact sheet (effective June 5, 2025): amendments permit conversion of existing carriage house structures into ADUs through installation of kitchens and bathrooms; conversions must still comply with all other carriage house standards; one parking space is required unless deed-restricted to low-income levels; new structures built to carriage house standards may be permitted as ADUs. HCD Finding 26 corrects the ordinance: a converted carriage house becomes an ADU and must be permitted as an ADU, not held to all CMC §86.56.110 standards. HCD Finding 19 confirms the carriage-house parking rule (max one space, none if deed-restricted affordable) with the same missing-state-exceptions caveat as Finding 17. Carriage houses are common in Coronado's historic neighborhoods per the city fact sheet — relevant context, not a rule.Separate sale (AB 1033) — nuanced, not a flat 'not adopted'
Ordinance §86.56.105.B.9 as quoted in HCD Finding 10 (state agency) bans separate sale entirely. Better Place (March 2026 page; underlying claim dated March 2025) states: 'as of March 2025, Coronado has not adopted such [an AB 1033 ordinance]' and 'ADUs cannot currently be sold separately from the primary residence' (builder guide). HCD Finding 10 corrects the blanket ban: state law §66341 requires allowing separate sale to a qualified buyer when its conditions are met (qualified nonprofit developer + sale at an affordable housing cost + local approval of compliant applications); the ban remains valid for JADUs only; the city 'should also consider' allowing ADU condominium subdivisions under §66342 (optional). Publish as: no AB 1033 condominium-conveyance ordinance adopted as of March 2025 (builder guide); however, HCD found the ordinance's blanket separate-sale ban noncompliant because §66341 qualified-buyer sales must be allowed — confirm current conveyance rules with the city; JADUs can never be sold separately. The County of San Diego's AB 1033 adoption applies to unincorporated areas only and must not be conflated with the City of Coronado.AB 956 (effective January 1, 2027) — to verify
No Coronado publication on how it will apply AB 956 was located. Builder-guide context only (SnapADU): AB 956 increases the state-exempt detached allowance under §66323 from one to two units beginning January 1, 2027, which could create a pathway to three detached ADUs when combined with a standard §66314 ADU, 'but that interpretation still needs further HCD guidance and confirmation from Coronado,' and the expanded allowance also changes whether a JADU must be approved. Publishable line: AB 956 takes effect January 1, 2027 (two detached ADUs per single-family lot under state law); how Coronado applies it is to verify. Do not publish any city-specific application, including any second-unit size cap.Rent calculator
Defaults below are EXAMPLES — editable placeholders, not verified local rent or cost data. Type your own numbers.
Verified builders in San Diego County
One metro-level profile per builder, linked from every city page they serve. Profiles are never duplicated per city, so a correction lands everywhere at once.
Frequently asked questions
Why does this page keep saying state law controls?
Because HCD's December 10, 2025 letter found Ordinance No. 2024-02 noncompliant on 31 points — including wrong unit caps, a six-month rental term, a blanket separate-sale ban, missing parking exceptions, and a replacement-parking rule state law bars. Until the city amends, the code figures on this page are the city's published text, and the state-law corrections are flagged beside them.
Do I need a coastal permit for an ADU in Coronado?
The entire City of Coronado is located in the Coastal Zone, and the city has a certified Local Coastal Program. Coastal review is integrated into standard city permitting — no separate CDP application or public hearing specifically for ADUs. State law requires the CDP process and the ADU permit process to happen concurrently unless the applicant requests otherwise; the ordinance's rule barring building permits before a coastal permit issues was flagged by HCD on that point. CDP fee, timeline beyond the builder-guide coastal estimate of 4–5 months, and waiver criteria: to verify.
Can I sell an ADU separately from the house in Coronado?
No AB 1033 condominium-conveyance ordinance adopted as of March 2025 (builder guide). However, HCD found the ordinance's blanket separate-sale ban noncompliant because §66341 qualified-buyer sales must be allowed — confirm current conveyance rules with the city. JADUs can never be sold separately. The County of San Diego's AB 1033 adoption applies to unincorporated areas only, not the City of Coronado.
Does Coronado offer pre-approved ADU plans?
Program in development as of June 2025 (city fact sheet: 'The City is developing pre-approved ADU plans that homeowners can utilize at no cost beyond standard permitting fees'). A city staff report for the March 25, 2026 Council meeting states permits were issued for two ADUs utilizing the city's preapproved ADU plans in 2025 — but that document's provenance needs verification before the figure is cited, and it is a partial count, not the city's total 2025 ADU permits. Plan sizes, plan count, cost, availability, and the 30-day track: to verify.
Sources
- HCD ordinance review letter, December 10, 2025 — 31 noncompliance findings (state agency, primary source)
- City of Coronado Housing Element Ordinance Amendments fact sheet (city-published, eff. June 5, 2025)
- Coronado Municipal Code Chapter 86.56 (city code portal)
- City of Coronado SB 9 handout — contact block (city-published)
- Coronado ADU regulations — SnapADU (builder guide)
- Coronado ADU regulations — Better Place (builder guide, March 2026)
Not legal advice. This page is a starting point, not a parcel approval. Confirm your lot with the city before you build, buy, or sign anything.
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