JADUs and Attached ADUs in Chula Vista, CA

Two ways to add a unit to the house

A JADU, or junior accessory dwelling unit, is carved out of space within the walls of a single-family home. Chula Vista's JADU rules are in CVMC 19.58.023. The unit needs an exterior entrance of its own and an efficiency kitchen, and it is allowed to share a bathroom with the main house. Because it uses rooms you already have, it often costs a fraction of any other legal unit.

An attached ADU is a complete second dwelling that shares at least one wall with the house: full kitchen, its own bathroom, its own entrance. It can be built as an addition, a second story, or by converting attached space larger than a JADU allows. Its rules sit with the other ADU standards in CVMC 19.58.022.

Both codes were last amended by Ordinance 3548 in 2023. A 2025 proposal to hand most of the detail over to state law went to the Planning Commission, but we could not confirm it was adopted, so read the City text alongside state law. Where the two differ, the less strict state rule controls.

JADU rules in Chula Vista

• Size: 500 sq ft at most, inside the existing or proposed house. An attached garage can count as part of the house under HCD's reading of state law; ask the City how it treats one.
• Kitchen: an efficiency kitchen, a compact cooking area rather than a full kitchen.
• Entrance: its own exterior door.
• Bathroom: may be private or shared with the house, which matters for owner occupancy (below).
• Parking: none, because it is part of the main home.
• Setbacks: none new, since nothing is added outside the walls.
• Rentals: more than 30 days only. JADUs cannot be short-term rentals under state law, and the City's short-term rental code excludes any ADU or JADU permitted since January 1, 2020.
• Sale: never separately. The City requires a recorded deed restriction.

Who has to live there

This is where the City code and state law currently disagree. CVMC 19.58.023 still requires the owner to live in either the main house or the JADU, recorded through a deed restriction. Since January 1, 2026, state law (AB 1154, now Gov Code 66333(b)) requires owner occupancy only when the JADU shares bathroom facilities with the main house. The City text has not been updated to match.

Our reading is that a JADU with its own bathroom should not trigger the owner-occupancy rule under state law, but the City has not confirmed how it applies the change. If you may move out and rent both the house and the JADU some day, ask Development Services in writing before you submit, and see whether the deed restriction they hand you still contains the occupancy language. Adding a small bathroom is often the cleaner path, which is why our calculator shows the shared-bath option as a warning.

Attached ADU size and height

The attached size limit in Chula Vista is the greater of two numbers: 50% of the main home's floor area, or a flat allowance of 850 sq ft (zero or one bedroom) or 1,000 sq ft (two bedrooms or more). On top of that, an 800 sq ft unit is always allowed, regardless of floor area ratio, lot coverage or open space rules.

From CVMC 19.58.022(C)(3). For houses above 2,400 sq ft, ask Planning what upper limit it applies; our calculator stops at 1,200 sq ft.

Height is the attached ADU's other advantage. It can reach 25 ft or the zone's height limit, whichever is lower, with no more than two stories. A detached unit is held to 16 or 18 ft. So on a lot with no room left in the yard, an ADU above an attached garage or a one-bedroom stacked over a rear addition can work where a backyard cottage cannot. New attached construction keeps 4 ft from the side and rear property lines. The rest of the detached limits are on the detached ADU page.

Permit and fees: where these units save money

City building permit

Chula Vista charges a flat permit fee for an attached ADU under Fee Bulletin 10-400 (Sept 2024): $2,380 for a one-story unit covering the first 300 sq ft, plus $423 for each additional 300 sq ft. A multi-story attached ADU starts at $2,698 plus $529 per additional 300 sq ft. A 550 sq ft one-story unit comes to about $2,803. The bulletin does not have a line clearly labeled for JADUs; our calculator uses about $1,604, the figure a third-party summary gives for conversions, and that should be confirmed with Development Services.

Impact and school fees

• JADUs pay no development impact or in-lieu fees at any size (Fee Bulletin 16-100, Oct 2025) and stay under the 500 sq ft line for school fees.
• Attached ADUs under 750 sq ft pay no impact fees either. Over 500 sq ft, school fees of about $5.38 per sq ft apply ($2.37 Chula Vista Elementary plus $3.01 Sweetwater Union).
• Attached ADUs of 750 sq ft and up pay a share of the single-family impact fees in proportion to the house. On the east side, where the park and Eastern traffic fees are highest, the full single-family total is about $57.7k against about $36.7k west of I-805.

A JADU also adds no new sewer demand in our calculator, while an attached ADU picks up the City sewer capacity charge ($4,793 per dwelling unit equivalent; the ADU factor is unconfirmed, so we use 0.79). For every fee line, see the ADU cost page.

Why east-side tract homes suit JADUs

The newer master-planned neighborhoods east of I-805 have a particular mix: larger floor plans, yards that are often modest, and, in many cases, both an HOA and a Mello-Roos district. That mix points toward a unit inside the house.

• The space is already there. If your floor plan has a downstairs bedroom suite or a three-car garage, a JADU uses that space instead of the yard. San Miguel Ranch's Van Daele homes, for example, ran 2,427 to 3,273 sq ft with three-car garages.
• The big east-side fees never start. East of I-805, a 750 sq ft attached ADU would start paying a share of the higher park and Eastern traffic fees. A JADU pays none.
• Less for the HOA to review. A JADU changes little on the outside, often just a door. Civil Code 4751 protects ADUs and JADUs in planned developments, but architectural review of exterior changes still applies.
• Mello-Roos questions are smaller. Several older CFDs, such as 07M in Eastlake and 12M and 13M in Otay Ranch, tax living square footage from building permits. A JADU inside existing walls adds no floor area, though you should still ask the City's CFD administrator how your district treats it.
• Rents are higher. RentCafe's October 2026 averages put Otay Ranch near $3,199 a month across all unit types, against about $2,198 for central Chula Vista.

The Eastlake and Otay Ranch ADU guide goes deeper on master associations and special tax districts. West-side owners with an older garage out back may find a garage conversion gives them a more private unit for a similar budget.

JADU vs attached ADU, side by side

Under state law, a lot may hold a JADU along with an ADU. From 2027, AB 956 says a JADU is not required where two detached ADUs are built.

JADU and attached ADU cost in Chula Vista

These midpoints come from our calculator for mid-range finishes, with design, reports, the City permit, any school and sewer charges and a 10% contingency inside. Attached figures assume a 1,600 sq ft house, flat ground and short utility runs.

Not bids. The JADU range is wide because the starting space varies so much: a finished bedroom with a bath next door costs far less than a garage bay with no plumbing.

A JADU usually rents as a studio, about $1,700 to $2,150 a month in Chula Vista, and an attached one-bedroom about $1,950 to $2,500 (Zumper and RentCafe in fall 2026; the eastern ZIP codes toward the top. Try your own layout in the JADU cost calculator or the attached ADU cost calculator.

The City's ADU Loan Program

The City's housing division has offered forgivable loans for small units, and for a JADU the cap goes a long way. Per the City's program sheet: up to $50,000 toward a new JADU, up to $100,000 toward a new ADU, and up to $50,000 for code repairs to an existing ADU or JADU. Payments are deferred, the loan accrues 3% simple interest, and after 15 years of renting under the City's regulatory agreement the debt is forgiven.

Eligibility is narrow. You need at least one year of owning and living in the house, no other real estate in your name, and a household income at or below moderate. The rental terms are set by that agreement, so read it closely. The 2023 housing report showed $200,000 earmarked for these loans, but whether the City is accepting new applications in 2026 is something we could not verify; ask before you plan around it. At our 300 sq ft midpoint, a $50,000 loan would cover about half the cost of a JADU.

For the full design and permit sequence, see the design-build process page. All work is done by a licensed San Diego general contractor.