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Building an ADU in San José

The most built-out ADU apparatus in the county: a dedicated ADU Ally team, an ADU permit service with same-day issuance for pre-approved plans, a 30-plus vendor pre-approved catalog, and the first ADU condominium sale in California under AB 1033.

Check a San José address → San José's ADU page →

Pre-approved plans

Checked 2026-09-10

City-reviewed plans from 30+ vendors. With a complete site-specific package the permit may issue the same day as the plan-review appointment. Under state law a detached unit built from a pre-approved plan gets a 30-day decision instead of 60.

Program page →

Programs and incentives

Active
Same-day permits for pre-approved plans

Pre-approved-plan projects go through the Permit Center's ADU service; the permit may issue the same day as the plan-review appointment when the site-specific submittal is complete.

San José's page → Checked 2026-09-10
Active
AB 2533 legalization path

Penalty-free path to legalise an ADU or JADU built without permits before 1 January 2020. Apply through the ADU Ally team. The city's own earlier amnesty window closed in January 2022.

San José's page → Checked 2026-09-10

Local rules worth knowing

Local standards. The city says its zoning code enacts state ADU law and its ADU Universal Checklist reflects it (Municipal Code 20.30.150). No city-specific dimensional standards beyond state law could be verified.
Sold separately. First California city to implement AB 1033: an ADU may be converted to a condominium and sold separately from the main home.
Separate meter. PG&E now requires a new ADU to have its own meter (JADUs do not). The site plan must show the sewer point of connection.
Trees. Removing an ordinance-size tree (38 in circumference at 4.5 ft, single or combined trunks) on a single-family lot needs a tree removal permit.
Tiny homes on wheels. Permitted as a type of ADU on single-family lots, with a simpler, lower-cost permit process.
Short-term rental. Minimum rental term is 30 days.

Who issues the permit

If the parcel is inside San José city limits, the City issues the permit and its ordinance applies on top of state law. Just outside the line it is Santa Clara County instead, with different standards.

San José's ADU page → Planning department → Online permit portal →

Contact. ADU Ally team: adu.ally@sanjoseca.gov, (408) 793-5302. Permit Center (408) 535-3555.

Review time

About 20 business days for the first round of building review on a standard submittal; the city publishes current averages and suggests adding two to three weeks for planning.

Fees

School and parkland impact fees do not apply under 750 sq ft; above that, parkland fees vary by location and the city publishes a park-fee map and a fee estimator.

How this was checked

Last gone over September 10, 2026. Verification: consistent evidence from the city's own pages in search results; most municipal sites refuse requests from our server. Programmes get suspended, capped and restarted; the links are the authority. Ask Keyli and she searches San José's own site live rather than answering from memory.

What's true in San José because it's true everywhere

State law sets a floor no ordinance can go under. The full guide, with every statute cited →

An ADU is allowed on your lot

Every lot zoned for residential use may have at least one ADU, and a single-family lot may also add a JADU. A city cannot say no to the category.

800 sq ft by right

A detached or attached unit of up to 800 sq ft, 16 ft tall, with 4 ft side and rear setbacks must be approved regardless of local lot-coverage or floor-area limits.

Four-foot setbacks

A city cannot require more than four feet from side and rear lot lines for an ADU.

A 60-day decision

Once your application is complete the city has 60 days to approve or deny; 30 if you build from a pre-approved plan.

No replacement parking

Convert or demolish a garage to build an ADU and the spaces you lose never have to be replaced.

No impact fees under 750 sq ft

Prohibited entirely below 750 square feet, and proportional above it.

Ministerial review

Reviewed against an objective checklist. No design review board, no hearing, no discretion about whether they like it.

No owner-occupancy rule for an ADU

A city cannot require you to live on the property for a standard ADU. A JADU is different: since 1 January 2026 owner occupancy is required when the JADU shares sanitation with the main house.

We build here

San José is inside our service area, and ADUs are all we do. We bring in the architect and engineer or work with yours, run the permit with San José, and build with our own crew: about 6 weeks of construction for a detached unit once the permit is in hand.

What we can't tell you from here is what your particular lot will take: setbacks, the sewer lateral, the panel, grade and access. That is what the free site walk is for.