Building an ADU in Newport Beach

Which rules apply in Newport Beach

Newport Beach has two ADU ordinances. Section 20.48.200 of the Municipal Code applies citywide outside the Coastal Zone. Section 21.48.200, part of the city's Local Coastal Program rules, applies inside the Coastal Zone. The city's ADU rules page says the current citywide rules were "Adopted August 26, 2025 and effective September 9, 2025."

Before that update, the state housing agency (HCD) reviewed the city's 2023 ordinance. Its October 2024 letter listed 13 ways it failed to comply with state law. Examples included owner-occupancy rules and deed restrictions on ADUs, a ban on selling ADUs separately in any case, and a rule that "Only one (1) of the categories" of ADU could be used per lot. The 2025 citywide rules no longer require owner occupancy for ADUs, and they say the unit limits apply "Unless precluded by Government Code Section 66323." The Coastal Zone section still contains the "Only one of the categories" wording.

The city's ADU website asks you to "Confirm all details with City staff while planning your ADU." Call the Planning Division at 949-644-3204. [1][2][4][5]

What you can build

ADUs and JADUs are allowed in every residential and mixed-use zone, and there's no minimum lot size. The city's ADU site says "Homeowners can build both an ADU and a JADU on their property."

• Single-family lot: one ADU (inside the house, attached, or detached) plus one JADU. State law also lets you combine a converted ADU, a new detached ADU of up to 800 sq ft with 4-foot side and rear setbacks, and a JADU on one lot. Ask Planning how the city applies that combination to your lot.
• Existing apartment or other multi-unit lot: ADUs converted from non-living space such as storage rooms, attics or garages (at least one, up to 25% of the existing units), and detached ADUs. Section 20.48.200 says up to two detached ADUs on a lot with an existing or proposed multi-unit building. The city's 2026 summary chart allows up to eight on a lot with an existing multi-unit building, not more than the number of existing units, and two on a lot with a proposed one. Ask Planning which number it applies to your lot.
• No JADUs on a lot with a multi-unit building.

[1][3][6][7]

Size, height and setbacks

These are the citywide rules in section 20.48.200. The Coastal Zone section uses the same size, height and setback numbers, but a larger setback can be required to protect coastal resources.

• Size: a new attached or detached ADU can be up to 850 sq ft for a studio or one bedroom, and 1,000 sq ft for two or more bedrooms. An ADU converted from space inside the house or an existing accessory structure has no size cap. A JADU can be up to 500 sq ft.
• 800 sq ft floor: floor-area limits, lot coverage, open space and the front setback can't shrink an ADU below 800 sq ft "where there is no other alternative to comply."
• Detached height: 16 feet. It's 18 feet within a half-mile walk of a major transit stop or high-quality transit corridor, plus 2 feet to match the house's roof pitch, and 18 feet on a lot with a multi-story, multi-unit building. An ADU above a detached garage can be two stories, up to the zone's height limit, if it meets the zone's setbacks.
• Attached height: the zone's height limit. HCD's 2024 letter said state law doesn't let a city require less than 25 feet or the zone's limit for the house, whichever is lower.
• Setbacks: at least 4 feet from side lot lines and rear lot lines not on an alley, unless the zone allows less. The front setback follows the zone. Converting existing space, or rebuilding a structure in the same footprint and size, needs no additional setback.
• Basements: the floor area of an ADU or JADU below grade in a basement doesn't count toward the floor-area limit. Digging out a walkout entrance is allowed only for exterior access, and the passageway must meet the code's width, length and location rules.

[1][2][5][6]

Parking and garage conversions

Outside the Coastal Zone, the city can require at most one parking space for each ADU. It can be tandem or on an existing driveway, but not in the front setback unless the driveway there is at least 20 feet deep. JADUs need no parking.

No parking is required for an ADU that is inside the house or converted from an existing accessory structure, or that is:

• within a half-mile walk of public transit (including a bus stop),
• in an architecturally and historically significant historic district,
• where on-street parking permits are required but not offered to the ADU occupant,
• within one block of a car-share vehicle, or
• outside the Coastal Zone, built along with a new home on the same lot.

State law requires that last exemption only when the ADU or the lot also meets one of the other exemptions; the city's list doesn't include that condition. Confirm with the Planning Division how it applies to your lot.

Garage conversions. Outside the Coastal Zone, the code says garage, carport and parking spaces removed or converted for an ADU "are not required to be replaced," and the same applies when a garage becomes a JADU. The city's ADU site and 2026 summary chart say replacement parking is required for a JADU garage conversion citywide. HCD's 2024 letter said requiring replacement parking when covered parking is converted into a JADU "is inconsistent with the Law." Ask Planning which rule it applies. Inside the Coastal Zone, garage parking removed for an ADU must be replaced. See our garage conversion guide. [1][2][3][5][6][7]

Building in the Coastal Zone

If your lot is in the Coastal Zone, section 21.48.200 applies instead of the citywide section. Use the city's Address Search Tool to check.

• Coastal Development Permit. You must get one unless the project is exempt or excluded. The code says no public hearing is held: neighbors get notice and can send written comments. The city's ADU site says the permit "could possibly require a hearing," so ask your planner.
• Coastal protections. The ADU must meet the coastal rules for bluffs, canyons, scenic views and habitat. Flood and sea-level-rise rules set the minimum floor height for new living space.
• One category per lot. The coastal section still says "Only one of the categories described below in this subsection may be used per lot." In its 2024 letter about the same wording in the citywide code, HCD said the ADU types listed in state law "can be combined" on a single-family lot. Ask Planning how the coastal rule is applied.
• Replacement parking. A garage, carport or covered parking removed for an ADU must be replaced on the lot, for example as uncovered, tandem or lift spaces.
• Deed restriction. Before the permit is issued, an ADU or JADU in the Coastal Zone needs a recorded deed restriction. In flood hazard areas it must include a flooding notice, and in low-lying shoreline areas you also record a waiver of future shoreline protection.

HCD's handbook says state ADU law applies in the Coastal Zone but doesn't "alter or lessen" Coastal Act protections. It also says that when a certified local coastal program has ADU rules, the city must approve or deny a coastal permit for an ADU within 60 days of a complete application when there's already a home on the lot, and isn't required to hold a public hearing. [2][5][7][8]

Fees

The city's ADU site lists these typical city fees:

• Plan check: due when you submit, "range from $850 to $1,700, based on valuation for conversions and floor area for new construction."
• Building permit: due when the permit is issued, "ranging from $850 and $2,100."
• School district fees: "apply to ADUs over 500 SF."
• Traffic Fairshare and Transportation Corridor fees: "apply to ADUs over 750 SF."
• Utility and sanitation fees: vary by the ADU's size and location. ADUs don't need separate water and sewer connections, but you may need to upsize your service or meter.

Under state law, an ADU with 750 sq ft of interior livable space or less pays no impact fees, and a larger one pays in proportion to the size of the house. ADUs under 500 sq ft don't pay school impact fees. The city points to the Orange County ADU calculator for an estimate. For typical building costs see our ADU cost guide. [1][7][8]

How long it takes

The code says a building permit for an ADU or JADU "shall be considered and approved ministerially, without discretionary review or a hearing, within sixty (60) days" after the city finds the application complete. That clock pauses if you ask for a delay. If you apply together with a new house, the city can wait until it decides on the house.

In practice, the city's ADU site says review comments come back "within 10-20 days," and "Most projects require 2-3 rounds of review." It puts permitting at 1 to 6 months and a whole ADU project at 12 to 18 months. State law also requires a written completeness decision within 15 business days. See our ADU permit process guide. [1][7][8]

Junior ADUs, owner occupancy and deed restrictions

A JADU is up to 500 sq ft, within or attached to a single-family home, with its own exterior entrance. It may also connect to the house inside. It can share a bathroom with the house and needs at least an efficiency kitchen. See our junior ADU guide.

Owner occupancy. The city doesn't require you to live on the property to have an ADU. For a JADU, the code says an owner must live in either the house or the JADU. Since 2026, state law requires that only if the JADU shares bathroom facilities with the house. Ask Planning how it applies to a JADU with its own bathroom.

Deed restrictions. Outside the Coastal Zone, the code requires a recorded deed restriction for a JADU only. The city's permit page still lists a signed, notarized deed restriction (no separate sale and no short-term rental) for ADUs. HCD's handbook says a city "cannot impose a deed restriction on an ADU." In the Coastal Zone, the coastal section requires one for both ADUs and JADUs. Confirm with your planner which form you'll be asked to record. [1][2][3][6][7][8]

Renting, selling and legalizing an existing unit

ADUs and JADUs may be rented, but not for 30 days or less, so short-term rentals such as Airbnb aren't allowed. An ADU can't be sold separately from the house, except under a state law for homes built by qualified nonprofits.

Unpermitted units. The city's Safe ADU program helps legalize ADUs and JADUs built without permits. The city says "Any ADU built before 2020 qualifies," and that the unit must be brought up to the current building code but not current zoning standards. In the Coastal Zone the unit can't harm coastal resources such as public views, access or habitat. You can ask questions without giving your address at the Permit Center or through the ADU Assist Form. [1][7][9]

Permit steps in Newport Beach

1. Check your lot

   Look up your zoning, utility providers and whether you're in the Coastal Zone on the city's Address Search Tool. [3][8]

2. Talk to Planning

   Walk in to the Permit Center at 100 Civic Center Drive (1st floor, Bay C), call 949-644-3204, or use the ADU Assist Form. The city says a meeting before you apply isn't required but may save time. [8][10]

3. Get a design or pick a standard plan

   Hire a designer, or use one of the city's ADU Standard Plans. With a standard plan, ask a Building Engineer at 949-644-3265 which supplemental documents you need. [11]

4. Apply for a Coastal Development Permit if needed

   In the Coastal Zone, you may first need a Coastal Development Permit unless your project is exempt or excluded. [2][8]

5. Prepare the application package

   Combine the plan check and building permit applications with a grant deed and the city's Housing Questionnaire. The city's permit page also lists a signed, notarized deed restriction; HCD says a city can't impose a deed restriction on an ADU, so confirm with your planner which form applies. [7][8]

6. Submit and pay plan check fees

   Submit in person at the Permit Center; the city's standard plans page says you can also apply through the CiViC portal. Plan check fees are due at submission. [8][11]

7. Answer review comments

   The city returns comments within 10 to 20 days per round; most projects need 2 to 3 rounds. This is also a good time to request an address for the ADU. [8]

8. Get the permit, build and pass inspections

   Pay building permit and other fees when the permit is issued. If the ADU is near overhead power lines or an easement, you need a Southern California Edison sign-off before the final permit. [3][8]

Pre-approved and sample plans

• ADU Standard Plans

  Pre-reviewed plans for three detached ADUs (448, 504 and 672 sq ft) in three styles, plus one-car and two-car garage conversions. [11]

Who to call

• Newport Beach Planning Division / Permit Center

  ADU questions, walk-in help, permit submittal (100 Civic Center Drive, 1st floor, Bay C; Mon-Thu 7:30-5:30, Fri 7:30-4:30)

  949-644-3204

  100 Civic Center Drive, Newport Beach, CA 92660

  [10]

• Newport Beach Building Division (Building Engineer)

  Supplemental materials for ADU Standard Plans

  949.644.3265

  [11]

Questions people ask