Building an ADU in Encinitas

What you can build in Encinitas

ADUs are a permitted use in all areas zoned for single-family or multifamily homes. The rules are in Encinitas Municipal Code section 30.48.040, subsections T (ADUs) and U (junior ADUs), and the city summarizes them in its ADU and JADU Guide (PLN-118, May 2025).

Single-family lots. The city code allows one attached or detached ADU with a house, plus one junior ADU (JADU). State law goes further: HCD says cities must allow at least one ADU converted from existing space, one JADU and one new detached ADU on the same single-family lot. The city code itself says state law controls where the two conflict.

Multifamily lots. You can convert non-living space in an existing apartment building (storage rooms, attics, basements, garages and similar) into ADUs, at least one and up to 25% of the existing units. For detached ADUs, the city's 2025 guide follows state law: up to eight on a lot with an existing multifamily building, but no more than the number of existing units, and two on a lot with a proposed one. The municipal code text still says two. JADUs aren't allowed with multifamily buildings.

Design. The ADU's building materials must be compatible with the main house. A new detached ADU must use electricity as the sole power source for all appliances, and solar panels may be required.

The city's code has not been updated since Ordinance 2022-11. The City Council started amendments for the 2023 state laws (Resolution 2023-25) and for SB 477's renumbering (Resolution 2024-110). Statewide rules are on our California page. [1][2][3][4][5]

Size, height and setbacks

Size. An attached or detached ADU can have up to 1,200 sq ft of living area or the living area of the main house, whichever is less. An 800 sq ft ADU, 16 feet high with 4-foot side and rear setbacks, is allowed regardless of the house size or the zone's lot coverage and floor area limits. The city's guide adds that when the main house is smaller, a studio or one-bedroom ADU can still be up to 850 sq ft, and a larger one up to 1,000 sq ft. A JADU can be up to 500 sq ft.

Height. It depends on where the ADU sits:

• Detached ADU using the reduced 4-foot setbacks: 16 feet, or 18 feet within a half mile of major transit (20 feet if it matches the main house's roof pitch). On a multifamily lot with a multi-story building, 18 feet.
• Attached ADU using reduced setbacks: 25 feet in the RR and RR-1 zones, 22 feet in RR-2 to R-25, and 25 feet in R-30.
• An ADU that meets the zone's normal setbacks, or sits directly above a garage, follows the zone's height rules (EMC Chapter 30.16).
• On R-3 to R-25 lots with an average slope over 10%, lower limits (12 or 16 feet) apply.

Setbacks. The front setback is the zone's normal setback, reduced only when needed to fit an 800 sq ft unit and no other option exists. Side and rear setbacks are the zone's setback or 4 feet, whichever is less. An ADU above a garage needs 4 feet. Converting an existing permitted structure, or rebuilding one in the same spot and size, needs no setback. Eaves can project up to 2 feet into the 4-foot setback.

Overlay zones. On qualifying Hillside/Inland Bluff lots, ADUs must stay off natural slopes of 25% or steeper. In the Coastal Bluff Overlay Zone, additions including ADUs are limited to 10% of the existing house's area or 250 sq ft, whichever is greater, and geotechnical setbacks apply. Ask Planning whether an overlay affects your lot. [2][3]

Parking

The city requires one parking space per ADU. It can be tandem on an existing driveway. No parking is required if the ADU is within a half mile of public transit (the city's guide counts the train station and all bus stops), in a historic district, entirely inside existing space with no added area, where on-street permits are required but not offered to the tenant, or within one block of a car share facility. A JADU never needs parking.

Replacement parking. The city's 2025 guide says that if you remove garage or uncovered parking to build an ADU, you must replace it on the lot only if the property is in the Coastal Zone, west of Coast Highway 101, between Swami's and La Costa Avenue. The code text is broader and says any removed required spaces must be replaced. State law says a city may not require replacement parking when a garage, carport or parking space is demolished for an ADU or converted to one, but HCD also notes that state ADU law doesn't lessen Coastal Act protections. If your lot is near the beach, confirm with Planning at 760-633-2710.

An ADU may be built above a garage only if no garage parking is lost, and if an ADU is built above a garage, the garage itself can't also be converted. [2][3][5]

Fees

City fees are waived. Encinitas waives its plan review and inspection fees for ADUs. You still pay required state fees, a postage fee if a coastal development permit is needed, and San Diego County Recorder fees to record the ADU covenant.

Impact fees. The city code bars impact fees on an ADU under 750 sq ft and on any JADU, and requires proportional fees above that. State law now exempts ADUs with 750 sq ft or less of interior livable space.

Water, sewer and school. After you apply, the city emails you water, sewer and school fee forms. You take them to each agency, get them signed, pay any fees, and upload them before the permit is issued. Your water district is either the San Dieguito Water District or the Olivenhain Municipal Water District. Utility hookup fees must be proportionate to the ADU's size or plumbing fixtures, and a JADU pays no sewer or water connection fees. School fees apply to units over 500 sq ft.

Other costs. A geotechnical report is needed for new construction of 500 sq ft or more, unless the building official waives it. A grading permit may be needed; ask Land Development Engineering. For typical costs see our ADU cost guide. [1][2][3][4][5]

How long it takes

Under state law, the city must tell you within 15 business days whether your application is complete, and approve or deny a complete application within 60 days when there is an existing home on the lot. A detached ADU that uses a preapproved plan must be approved or denied within 30 days. The city code also sets 60 calendar days for coastal development permits, "to the extent feasible."

The city says the first round of review takes about 15 working days. Building, Planning, Fire Prevention and Land Development Engineering each review the plans, and redlines are released once all of them are done. Talking to each reviewer before you resubmit can cut down the number of rounds. Once you have a permit, inspections requested by 3 p.m. on a business day happen the next business day. See our ADU permit process guide. [1][3][5]

Building in the Coastal Zone

In the Coastal Zone, an ADU or JADU needs a coastal development permit (CDP) if it isn't completely inside the existing house, adds habitable area, or converts non-habitable space such as a garage. This includes legalizing an unpermitted unit.

You still apply for the building permit first. The planner opens a separate CDP record and asks for a reduced plan set, the grant deed and a title report. You post a notice sign on the property and upload a certificate of posting with a photo. The city mails a legal notice with a 10-day comment period, then issues a Notice of Decision. You must sign and notarize an indemnification agreement and return the original. If your lot is in the Coastal Commission's appeal jurisdiction, there is a further 10-business-day appeal period after the Commission receives the city's notice. The building permit can't be issued until the CDP is.

State ADU law applies in the Coastal Zone but doesn't lessen Coastal Act protections, and HCD says a CDP for an ADU must be decided within 60 days of a complete application. [1][2][3][5]

Garage conversions and junior ADUs

Garage conversions. Converting an existing permitted garage or other accessory building needs no setback (beyond fire and safety rules), may add up to 150 sq ft for entry and exit, and needs no new parking if no area is added. You don't need a separate utility connection for a conversion inside existing space with its own exterior entrance. Fire sprinklers aren't required if the house doesn't have them. In the Coastal Zone, converting non-habitable space needs a CDP, and the replacement parking rule above may apply near the beach. More in our garage conversion guide.

Junior ADUs. A JADU is up to 500 sq ft inside a single-family house or attached garage. It needs a separate exterior entrance and an efficiency kitchen with a cooking appliance, counter, storage and its own sink. It can have its own bathroom or share one; if it shares, it must have interior access to the house. JADUs pay no impact fees and need no parking. See our junior ADU guide.

Owner occupancy. The city's code and guide require the owner to live in the house or the JADU. Under state law in effect since January 1, 2026, owner occupancy is required only when the JADU shares bathroom facilities with the house. The city's rule is older than that change, so ask Planning which rule it applies. [2][3][5]

Renting, selling and legalizing

You don't have to live on the property to have an ADU. ADUs and JADUs may be rented only for terms longer than 30 days, so they can't be short-term rentals. Before the permit is issued you must sign, notarize and record a covenant that bars selling the unit separately and using it as a short-term rental, and limits its size.

Unpermitted units. Under state law, the city can't deny a permit to legalize an ADU or JADU built before January 1, 2020, just because it breaks building codes, unless correcting the problem is needed to fix a condition that makes the building substandard. Substandard conditions must still be corrected. Encinitas's Substandard Building Checklist (BLD-167) explains the process. You may get a confidential inspection from a licensed contractor, architect or engineer first; if you don't, a city inspector does a pre-inspection. Local ADU rules and the energy and CALGreen codes are waived, but Coastal Zone and coastal bluff rules still apply.

SB 9. State law lets you combine SB 9 units with ADUs. After an SB 9 lot split, each new lot only has to be allowed two units in total, counting ADUs. See our SB 9 guide. [2][3][5][6]

Permit steps in Encinitas

1. Talk to city staff

   Read the ADU and JADU Guide and consult Planning, Building, Fire Prevention, Land Development Engineering and your water district before or while you draw plans. Planning can tell you about overlays, slopes, height limits and whether you need a coastal development permit. [1]

2. Prepare plans and forms

   You need full plans (site, floor, elevations, roof, structural, electrical, plumbing), a grading plan if needed, the Stormwater Intake Form, the Housing Development Tracking Form, a current grant deed with legal description and a preliminary title report no more than 6 months old. Or use a Permit-Ready ADU plan with a site-specific plan. [1][4]

3. Apply online

   Submit through the Customer Self-Service Portal. Building technicians check that the submittal is complete and route it to each division. [1]

4. Get outside agency sign-offs

   The city emails you water, sewer and school fee forms. Take them to each agency, get signatures, pay their fees, and upload the final forms before the permit can be issued. [1]

5. Get a coastal development permit if needed

   In the Coastal Zone, the planner opens a CDP record. You post a notice sign, pay postage for the legal notice, and sign a notarized indemnification agreement after the decision. The appeal area adds a 10-business-day Coastal Commission appeal period. [1][2]

6. Respond to corrections and record the covenant

   Review takes about 15 working days per round. Resubmit corrected plans through the portal. Sign and notarize the ADU covenant, return the original, and pay the county recording fees. [1]

7. Get the permit, build and pass inspections

   The permit is issued once every division approves and all forms are in. Your contractor schedules inspections through the portal; if a height certification is required, Planning must approve it before the roof nailing inspection. [1]

Pre-approved and sample plans

• Permit-Ready ADU (PRADU) plans from the city

  Eight downloadable preapproved plan sets by Design Path Studio (350, 555, 745 and 938 sq ft) and DZN Partners (224, 499, 990 and 1,199 sq ft), with options for exterior materials and windows; no modifications allowed. [1]

• Privately prepared preapproved ADU plans

  Since January 1, 2025, designers can get non-site-specific ADU plans preapproved by the city under AB 1332 and then use them on individual lots. [1]

Who to call

• Encinitas Land Development & Building (Planning)

  ADU zoning rules, coastal development permits, covenants and preapproved plans; email planning@encinitasca.gov

  760-633-2710

  505 S. Vulcan Ave., Encinitas, CA 92024

  [1][2]

• Encinitas Building Division

  Building permits, plan check, building code, solar and inspections; email building@encinitasca.gov

  760-633-2730

  505 S. Vulcan Ave., Encinitas, CA 92024

  [1][7]

• Encinitas Fire Prevention

  Fire code, fire sprinklers and High Fire Severity Zone questions; email fireprevention@encinitasca.gov

  760-633-2820

  [1]

Questions people ask