Permits & Laws — City of San José

City of San José ADU Permits in 2026: Universal Checklist, Rules & Timelines

Updated June 2026 · ~9 min read

San José has been permitting ADUs since 2015 and has built one of California's most homeowner-friendly programs: no parking requirements, no owner-occupancy rule, a dedicated ADU permit service, and a choice between City and State design standards so you can pick whichever lets you build the unit you want. This guide walks San José homeowners through the official ADU Universal Checklist (Bulletin #210), the qualify-first steps, fire-safety requirements, size and setback rules, fees, and the 2026 state-law deadlines.

Step 1: Does your property qualify?

San José's ADU Universal Checklist starts by confirming your property is even eligible. Before you design anything, verify the following at SJPermits.org:

• The property is inside the City of San José (the "Incorporated" field reads "yes")
• The main home is legally permitted (single-family, duplex, or multifamily)
• There's no active Code Enforcement case on the property

Then check the property "designations" that shape your design — these are the most common sources of redesigns:

• Flood zone (A, AE, AH, AO) triggers special design requirements (Bulletin #211)
• Geohazard / liquefaction / landslide zones require a geologic hazard clearance
• Historic property status adds simplified design standards if you use City standards
• Wildland-Urban Interface (WUI) zones require WUI fire-conformance construction
• Easements and nonbuildable areas (e.g., a demolished pool) can block construction where you planned the ADU

City vs. State development standards — your big choice

San José lets you design your ADU under either City standards (Municipal Code 20.80.175) or State standards (20.80.176) — but you can't mix them. The choice changes your maximum size, setbacks, and height, so pick the set that unlocks the unit you actually want.

Rule of thumb: if you want the biggest possible unit, City standards usually win (up to 1,200 sq ft). If you want the fewest siting restrictions for a smaller footprint, State standards are simpler. Minimum size is 150 sq ft either way.

Size, setbacks & height at a glance

For most single-family homeowners building one detached ADU under City standards: up to 1,200 sq ft (on a 9,000+ sq ft lot), a 0-ft first-story side/rear setback, 18 ft single-story height, sited behind the main home with at least 6 ft of separation and no more than 40% rear-yard coverage. A JADU is capped at 500 sq ft within the existing home and requires owner-occupancy unless it has its own sanitation facilities.

Fire-safety requirements (the part that delays permits)

San José's Fire Bureau reviews every ADU, and missing fire items is the top cause of permit delays. Your site plan and application must address:

• Addressing: show premises identification for both the main home and the ADU; ADUs get a unit number visible from the street (Form #302 to request an address)
• Access: no more than 150 ft from the street curb to the farthest side of the ADU, along a minimum 4-ft clear path
• Hydrant proximity: the farthest exterior wall within 600 ft of a fire hydrant (mark hydrants on the vicinity map)
• Water flow: a minimum 1,000 gpm at 20 psi at the closest hydrant — request the water-flow letter from your water company early and submit it with your application; waiting on it is a leading cause of delay
• Sprinklers: if the main home has fire sprinklers, the ADU needs them too; attached ADUs over 500 sq ft that push the combined home over 3,600 sq ft trigger full sprinklering

Parking & owner-occupancy

Both the City and State standards require no parking for ADUs in San José. And since 2020, owner-occupancy is not required for an ADU — you can rent both the main home and the ADU. The exception is a JADU, which requires the owner to live on-site unless the JADU has its own independent sanitation facilities (and a Form 313 JADU deed restriction is recorded).

Pre-approved / Master Plan program

San José runs a pre-approved ADU program (its Single-Family Master Plan Program) where vendor designs are reviewed once and reused to speed up permitting. To use a pre-approved plan, your lot must be zoned residential with an existing single-family home or duplex, and it generally can't be in a geohazard, landslide, flood, or Wildland-Urban Interface zone. If a pre-approved model fits, you skip most of the design review.

2026 timelines & state law

Fees and exemptions

San José ADUs pay building-permit and plan-review fees (plan review is billed at an hourly rate for custom plans). The key state-law break: ADUs under 750 sq ft are exempt from school and parkland impact fees. At 750 sq ft or larger, those impact fees apply and your permit won't issue until they're paid — staff provide a school-fee referral form at submittal. Check the City's Fees for ADUs page for current amounts before you finalize your size.

How to apply

San José uses online permitting through SJPermits.org and electronic plan submittal via SJePlans, plus a dedicated ADU permit service. To keep things moving:

• Complete the ADU Universal Checklist (Bulletin #210) first — it catches disqualifiers before you spend on design.
• Decide City vs. State standards early — it sets your size, setbacks, and height.
• Request your hydrant water-flow letter now — don't let it hold up issuance.
• Use the ADU Ally team (ADU.Ally@sanjoseca.gov, 408-535-3555) for free help, or a pre-approved plan to shortcut review.

Frequently asked questions

How big can an ADU be in San José?

Under City standards, a detached ADU can be up to 1,000 sq ft on lots under 9,000 sq ft and up to 1,200 sq ft on larger lots. Under State standards, new detached ADUs are capped at 800 sq ft. The minimum is 150 sq ft.

What's the difference between City and State ADU standards?

They're two alternative rule sets you choose between (you can't mix them). City standards generally allow a larger ADU (up to 1,200 sq ft) with a 0-ft first-story setback; State standards cap new detached units at 800 sq ft but impose fewer siting restrictions.

Do I need parking for an ADU in San José?

No. Neither the City nor State standards require parking for ADUs in San José.

Do I have to live on the property?

Not for a standard ADU — owner-occupancy hasn't been required since 2020. A JADU requires the owner to live on-site unless the JADU has its own independent sanitation facilities.

Why do San José ADU permits get delayed?

The most common cause is the fire hydrant water-flow letter (1,000 gpm at 20 psi). Request it from your water company early and submit it with your application so it doesn't hold up issuance.

How fast can I get an ADU permit?

Pre-approved plans must be approved within 30 days, and any complete, code-compliant application within the 60-day state cap. SB 543 gives the City just 15 days to determine completeness.

Sources & further reading: City of San José — Accessory Dwelling Units · ADU Universal Checklist (Bulletin #210) · Pre-approved ADUs · State law summaries: AB 462, AB 1154, AB 1332, and SB 543 (effective 2025–2026).

This guide is for general information and reflects rules as of June 2026. Always confirm current requirements with the City of San José Development Services for your specific property before submitting.