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Can I build an ADU in Coronado, California?

Coronado, San Diego County · Ordinances checked 2026-10-05 · Reviewed · 12 cited sections

Allowed with a permit

Yes. Any residentially zoned Coronado property can apply for an ADU or junior ADU (JADU) permit, which the Community Development Director decides, and ADUs can't be used as short-term vacation rentals. This comes from the City's June 2020 application form and a 2025 summary of code changes; we couldn't get the current ADU code section, so size, height and setback limits aren't shown here.

Where allowedProperty must be zoned for residential use [1]
Types acceptedNew attached, new detached, conversion of living space or an accessory structure, JADU [2]
Who decidesCommunity Development Director [3]
Completeness reviewCity has 60 days to deem the application complete or incomplete [4]
Parking for deed-restricted affordable ADUsExempt from parking requirements [6]
Carriage house conversion parking1 space unless deed-restricted to low-income levels [7]
Short-term rentalsADUs and JADUs may not be rented short-term [5]

Where and what kind

Coronado's ADU rules are in Municipal Code Section 86.56.105. A property must be zoned for residential use to qualify for an ADU or JADU permit [1]. The City's application lists the types it accepts: a new attached ADU, a new detached ADU, conversion of existing living space, conversion of an existing accessory structure, or a JADU [2]. For conversions, you submit copies of the building permits for the existing structure [8].

Approval process

Applications go to the Community Development Department and must be complete; faxed applications aren't accepted [9]. The Community Development Director reviews the request and makes the decision [3]. The City has 60 days to decide whether an application is complete [4].

2025 changes: parking and carriage houses

Zoning amendments effective June 5, 2025 updated Section 86.56.105 to match state ADU law as of adoption [12]. ADUs deed-restricted to low, very low or extremely low-income levels are fully exempt from parking requirements [6]. Existing carriage house structures can now be converted into ADUs by adding a kitchen and bathroom. A converted carriage house still has to meet all other carriage house standards and needs one parking space unless it's deed-restricted to low-income levels [7]. New structures built to carriage house standards may also be permitted as ADUs [10]. The City is also developing free pre-approved ADU plans [11].

Rentals

ADUs and JADUs may not be rented as short-term vacation rentals [5]. State law separately requires that ADUs and JADUs approved under its by-right rules be rented, if at all, for more than 30 days.

What we couldn't check

We couldn't download the current Section 86.56.105, so we can't confirm size limits, setbacks, height or owner-occupancy rules. The application form we have dates from June 2020. The state's housing department issued ADU findings to Coronado in December 2025, so the rules may change again. State ADU law sets minimums the City must allow and may override conflicting local limits (see the state rules on this page). Starting January 1, 2027, state law (AB 956) will allow two new detached ADUs by right on a single-family lot.

See how Coronado compares with 8+ other California towns on accessory dwelling units (adus) →

Next steps

  1. Confirm your lot's zone and ask the Planning Division ((619) 522-7326, commdev@coronado.ca.us) for the current Section 86.56.105 standards, including size, height and setbacks.
  2. Ask whether the City's pre-approved ADU plans are available yet, which can cut design costs.
  3. Fill out Handout 721 (ADU application) with lot size, zone, ADU square footage, bedrooms, bathrooms and parking, and attach permits for any structure you're converting.
  4. File the complete package in person or by email with the Community Development Department at 1825 Strand Way; the Director decides, then you apply for building permits.

Common questions

Can I build an ADU in Coronado, California?
Yes. Any residentially zoned Coronado property can apply for an ADU or junior ADU permit, including new attached or detached units and conversions of living space or an accessory structure. The Community Development Director decides. The current code's size, height and setback limits couldn't be confirmed, so ask the Planning Division.
What are the ADU regulations in Coronado, California?
Coronado's ADU rules are in Municipal Code Section 86.56.105, updated effective June 5, 2025 to match state ADU law. The current section's size, height, setback and owner-occupancy rules couldn't be confirmed, and the state issued ADU findings to Coronado in December 2025, so the rules may change again.
Does an ADU need parking in Coronado, California?
It depends. ADUs deed-restricted to low, very low or extremely low-income levels are fully exempt from parking requirements. A converted carriage house needs one parking space unless it's deed-restricted to low-income levels.
Can I Airbnb my ADU in Coronado, California?
No. ADUs and junior ADUs in Coronado may not be rented as short-term vacation rentals. State law also requires ADUs approved under its by-right rules to be rented, if at all, for more than 30 days.
How long does ADU approval take in Coronado, California?
The City has 60 days to decide whether an ADU application is complete or incomplete. The Community Development Director then reviews and decides the request, after which you apply for building permits.

California's statewide ADU law

California's ADU law (Gov. Code §§66310–66342, recodified from §65852.2; latest amendments effective January 1, 2026) overrides conflicting city rules, including in charter cities. Cities must approve ADUs ministerially (no hearing) within 60 days of a complete application, or the permit is deemed approved.

What cities cannot require or do:

  • Owner-occupancy for an ADU.
  • A minimum lot size.
  • Side or rear setbacks over 4 feet for a new ADU, or any setback for a converted existing structure.
  • Size, lot coverage or floor-area rules that block an ADU of at least 800 sq ft. Size caps can't be under 850 sq ft (1,000 for 2+ bedrooms).
  • Parking within half a mile walking distance of public transit, or replacement parking for a garage converted to an ADU.
  • Impact fees on ADUs of 750 sq ft or less.

By right on a single-family lot: one converted ADU plus one junior ADU (JADU, up to 500 sq ft inside the house), plus one new detached ADU (up to 800 sq ft, 16 ft tall). Owner-occupancy may be required only for a JADU that shares a bathroom.

Short-term rentals: cities may bar ADU rentals under 30 days, and must for by-right ADUs, JADUs and SB 9 units.

Coming January 1, 2027: AB 956 raises the by-right count to two new detached ADUs per single-family lot.

SB 9 (§§65852.21, 66411.7) allows two homes on a single-family lot, or a split into two lots of at least 1,200 sq ft (with a 3-year owner-occupancy affidavit).

State sources: Gov. Code §66314 (ADU ordinance standards) · Gov. Code §66315 (no owner-occupancy requirement) · Gov. Code §66317 (ministerial review, 60-day deadline) · Gov. Code §66321 (size, setback and height limits on local rules) · Gov. Code §66322 (parking exemptions) · Gov. Code §66323 (by-right ADUs and JADUs) · Gov. Code §66333 (junior ADUs) · Gov. Code §66311.5 (impact fees) · AB 956 (2026), Stats. 2026, ch. 791 · Gov. Code §65852.21 (SB 9 two-unit projects) · Gov. Code §66411.7 (SB 9 urban lot splits) · HCD, Accessory Dwelling Units (ADU Handbook, updated March 2026)

What the ordinance says

Exact text from Coronado's published ordinances. Section numbers are as printed in the source.

  1. Handout 721, Notes, item 3, Handout 721 - Accessory Dwelling Unit (ADU) application (June 2020), p. 2
    3. A property must be zoned for residential use in order to qualify for an ADU/JADU permit.
  2. Handout 721, Type of Accessory Dwelling Unit Proposed, Handout 721 - Accessory Dwelling Unit (ADU) application (June 2020), p. 1
    New attached ADU Conversion of existing accessory structure New detached ADU JADU* Conversion of existing living space*
  3. Handout 721, Notes, item 5, Handout 721 - Accessory Dwelling Unit (ADU) application (June 2020), p. 2
    5. The Community Development Director considers a request for an ADU/JADU Permit and renders a decision.
  4. Handout 721, Notes, item 6, Handout 721 - Accessory Dwelling Unit (ADU) application (June 2020), p. 2
    6. In order to be reviewed for processing, applications must be deemed complete. The City has 60 days to determine the application complete or incomplete.
  5. Handout 721, Notes, item 4, Handout 721 - Accessory Dwelling Unit (ADU) application (June 2020), p. 2
    4. ADUs and JADUs may not be rented as short-term vacation rentals.
  6. Parking Requirement Reductions, Housing Element Ordinance Amendments Fact Sheet (zoning changes effective 6-5-2025), p. 2
    Accessory Dwelling Units (ADUs) that are deed-restricted to low, very low, or extremely low-income levels are exempt from parking requirements entirely
  7. Accessory Dwelling Unit (ADU) Provisions - Carriage House Conversions, Housing Element Ordinance Amendments Fact Sheet (zoning changes effective 6-5-2025), p. 2
    The amendments permit the conversion of existing carriage house structures into ADUs through the installation of kitchens and bathrooms. These conversions must still comply with all other carriage house standards. One parking space is required for the ADU unless the unit is deed-restricted to low-income levels.
  8. Handout 721, Type of Accessory Dwelling Unit Proposed, Handout 721 - Accessory Dwelling Unit (ADU) application (June 2020), p. 1
    *Submit copies of building permits for the existing structure to be converted
  9. Handout 721, Notes, item 1, Handout 721 - Accessory Dwelling Unit (ADU) application (June 2020), p. 2
    1. Application packages for an ADU/JADU Permit shall be filed with the City of Coronado Community Development Department. Faxed applications will not be accepted.
  10. Accessory Dwelling Unit (ADU) Provisions - Carriage House Conversions, Housing Element Ordinance Amendments Fact Sheet (zoning changes effective 6-5-2025), p. 2
    *New structures built to carriage house standards may be permitted as ADUs.
  11. Pre-Approved ADU Plans, Housing Element Ordinance Amendments Fact Sheet (zoning changes effective 6-5-2025), p. 2
    The City is developing pre-approved ADU plans that homeowners can utilize at no cost beyond standard permitting fees.
  12. Accessory Dwelling Unit (ADU) Provisions, Housing Element Ordinance Amendments Fact Sheet (zoning changes effective 6-5-2025), p. 2
    CMC Chapter 86.56.105 has been updated throughout to comply with the current State ADU laws at the time of adoption.
This page summarizes Coronado's posted ordinances as of 2026-10-05. Ordinances are amended, and individual lots can have overlays, subdivision covenants, or HOA rules that are stricter. Confirm with Community Development Department - Code Enforcement / Building Services, City Hall, 1825 Strand Way (Planning 619-522-7326; STR hotline 619-500-9625) (619-522-7331) before you build. Spot an error?