We ran 178,404 single-family lots across 28 San Jose ZIP codes through the same eligibility check behind our free address tool. 73.6% can fit a detached ADU, but the share runs from 37.1% in 95133 to 94.8% in 95117, so your ZIP code matters. This guide covers how your area compares, what the City of San José requires, what it costs, and the rules that most often slow projects down.
How many San Jose lots can fit an ADU?
- 73.6% of lots can fit a detached ADU.
- 37.7% have room for our largest model, the 800 sq ft EVO Two Plus.
- 26.4% need a closer look before anyone can give a clear answer.
The highest shares are in 95117 (94.8%), 95135 (94.1%) and 95123 (91.8%). The lowest are in 95133 (37.1%), 95131 (38.2%) and 95122 (42.9%). ZIP codes don't match neighborhoods exactly, but 95125 covers much of Willow Glen (72.6%), 95124 much of Cambrian (83.6%) and 95120 much of Almaden Valley (86%).
Lot size is only part of the answer. Median lots run from 5,358 sq ft in 95116 to 8,527 sq ft in 95120, and the median buildable area after setbacks runs from 2,537 to 4,877 sq ft. (Those ranges leave out ZIP codes with fewer than 1,000 lots.) But 95133 and 95111 have nearly the same median lot (6,068 and 6,026 sq ft), and 37.1% and 86.9% of their lots can fit an ADU. Your own lot can differ a lot from the ZIP average.
These figures come from California ADU law, parcel shape, existing building footprints, a 4-foot setback, CAL FIRE hazard zones and FEMA flood maps. They don't use San José's own zoning layer, so treat them as a starting point, not a decision on any one property.
San Jose ADU rules to know
The City of San José builds state ADU law into its zoning code and keeps its current requirements in the ADU Universal Checklist. Start there: it is the city's own test of whether your property qualifies, and it covers setbacks, height and fire requirements.
- Where ADUs are allowed: residentially zoned properties, including single-family, duplex and multifamily lots.
- State baseline: California law generally protects a detached ADU of up to 800 sq ft with 4-foot side and rear setbacks. The city asks applicants to say whether they are using its "City allowance" or "State allowance" option.
- Renting: you can build an ADU where the main house is a rental, and rent the house and the ADU to different parties. The minimum rental term is 30 days, including on Airbnb.
- Utilities: the city says PG&E now requires ADUs to have their own meter. Confirm with PG&E's Building and Renovation Service Center at (877) 743-7782.
- Gas: the city has paused enforcement of its natural gas ban, so gas or all-electric is allowed. Every EVO is all-electric.
- Property tax: your taxes go up based on the value of the ADU.
- Selling: to sell an ADU separately from the house, you must first apply for a condominium conversion.
Fire rules that slow projects down
San José's Bureau of Fire Prevention reviews ADU plans against the California Fire Code. These checks, from the city's ADU FAQ, are worth doing before you pick a spot in the yard:
- Access: every part of the ADU should be within 150 feet of the street curb, measured along a clear path at least 4 feet wide. If not, you may need a Fire Variance.
- Hydrant distance: all exterior walls should be within 600 feet of a fire hydrant.
- Water flow: the city looks for 1,000 gpm at 20 psi from the closest hydrant, and you submit a letter from your water company with your application. The city says projects are often delayed because applicants don't get this letter, so request it early.
- Sprinklers: if your main home has fire sprinklers, the ADU must have them too.
Fees: why 750 square feet matters
San José bases its building permit fee on the size of the ADU, and its Building Fee Estimator gives a general idea of the cost. The number to watch is 750 sq ft: school fees and parkland fees don't apply to ADUs under that size. At 750 sq ft or more, ask your school district about its fees and check the city's parkland fee map, because those fees vary by location. Some lots also need geological hazard review, a tree removal permit or a fire variance, each with its own fee.
Four of our five models are under the line:
| Model | Size | Layout | Unit price | Under 750 sq ft? |
|---|---|---|---|---|
| EVO Compact | 350 sq ft | Studio, 1 bath | $145,800 | Yes |
| EVO Studio | 430 sq ft | Studio, 1 bath | $157,920 | Yes |
| EVO One | 560 sq ft | 1 bed, 1 bath | $179,680 | Yes |
| EVO Two | 715 sq ft | 2 bed, 1 bath | $203,050 | Yes |
| EVO Two Plus | 800 sq ft | 2 bed, 2 bath | $238,000 | No |
Complete projects, delivered and installed, start from $189,540 for the EVO Compact. City permit fees are separate. See how that compares in our prefab ADU price comparison, and read about financing.
How long do San Jose ADU permits take?
The city says the first round of building review typically takes 20 business days, unless your plan needs additional review. Accurate, complete plans help you stay within one or two review cycles. The city's process runs in six steps:
- Complete the ADU Universal Checklist.
- Prepare your plans, including Title 24 energy calculations and the water flow letter.
- Start your application on SJPermits.org.
- Upload your plans and documents to SJePlans.
- Go through prescreen, plan review and issuance, paying fees along the way.
- Build, pass inspections and get your final sign-off.
For questions, the city's ADU Ally team is at adu.ally@sanjoseca.gov or 408-793-5302. A preliminary virtual meeting with a planner is billed at $398 an hour, with a 30-minute minimum.
With EVO, we handle permit submissions, plan review responses and building department communications for you. Most EVO projects take about 6 months from contract to move-in, though timelines vary by jurisdiction and site conditions.
Preapproved plans and same-day permits
San José also runs a Preapproved ADU program: standard plans already reviewed by city staff, offered by the vendors the city lists. If your site-specific documents are accurate and complete, permits may be issued the same day as your plan review meeting. To qualify, your lot must be zoned residential with an existing single-family home or duplex, and must not be in a geohazard zone, landslide zone, flood zone or Wildland-Urban Interface area.
Flood zones can rule this out. In our data, 25.2% of lots in 95110, 22.1% in 95116 and 16.2% in 95125 are in a FEMA flood zone, as is every lot in 95002 (Alviso). Check your address on SJPermits.org to confirm.
What can an ADU rent for in San Jose?
HUD's fair market rent for a one-bedroom runs from $2,190 a month in 95111 to $4,060 in 95134. Zillow's typical asking rent, which covers all home sizes, runs from $2,409 in 95130 to $5,209 in 95120. Actual rent depends on size, finish, parking and privacy, so treat these as area figures, not a quote. See our ADU rental income guide for more.
San Jose ADU data by ZIP code
| ZIP code | Lots analyzed | Can fit an ADU | Median lot | Best-fit EVO |
|---|---|---|---|---|
| 95117 | 3,044 | 94.8% | 7,070 sq ft | Two Plus |
| 95135 | 4,324 | 94.1% | 8,006 sq ft | Two Plus |
| 95123 | 12,678 | 91.8% | 6,175 sq ft | Two Plus |
| 95128 | 5,740 | 90.9% | 6,291 sq ft | Two Plus |
| 95119 | 2,699 | 90.8% | 6,210 sq ft | Two Plus |
| 95129 | 7,886 | 87.7% | 6,432 sq ft | Two Plus |
| 95111 | 7,584 | 86.9% | 6,026 sq ft | Two Plus |
| 95130 | 3,291 | 86.7% | 6,266 sq ft | Two Plus |
| 95120 | 11,698 | 86% | 8,527 sq ft | Two Plus |
| 95124 | 13,405 | 83.6% | 6,624 sq ft | Two Plus |
| 95148 | 10,736 | 82.9% | 6,505 sq ft | Two Plus |
| 95139 | 1,782 | 82.8% | 6,171 sq ft | Two Plus |
| 95121 | 7,293 | 82.3% | 6,329 sq ft | Two Plus |
| 95138 | 4,221 | 81.9% | 6,739 sq ft | Two Plus |
| 95136 | 7,083 | 74.6% | 6,168 sq ft | Two Plus |
| 95125 | 12,609 | 72.6% | 6,898 sq ft | Two Plus |
| 95118 | 7,839 | 70.3% | 6,289 sq ft | Two Plus |
| 95126 | 3,906 | 61.6% | 6,026 sq ft | Two Plus |
| 95002 | 397 | 60.7% | 6,315 sq ft | Two Plus |
| 95127 | 12,352 | 60.1% | 6,470 sq ft | Two Plus |
| 95112 | 4,994 | 56.2% | 5,891 sq ft | Studio |
| 95110 | 2,033 | 53.9% | 5,402 sq ft | Studio |
| 95132 | 9,420 | 52.5% | 6,307 sq ft | Two Plus |
| 95116 | 4,963 | 43.5% | 5,358 sq ft | Studio |
| 95134 | 214 | 43.5% | 3,241 sq ft | Two Plus |
| 95122 | 7,593 | 42.9% | 5,508 sq ft | One |
| 95131 | 4,772 | 38.2% | 5,499 sq ft | Two Plus |
| 95133 | 3,848 | 37.1% | 6,068 sq ft | Two Plus |
Click a ZIP code for its full page. ZIP boundaries don't match city limits exactly. 95134 (214 lots) and 95002 (397 lots) are small samples.
Next steps
Neighborhood figures only go so far. Check your exact address for free, compare our five models, or book a free consultation and we'll look at your lot with you.
Sources: City of San José ADU pages, checked October 30, 2026; EVO ADU census (rules engine v1.0.2, 2026-07-25), HUD Fair Market Rents and Zillow's rent index. Rules and fees change, so confirm current requirements with the city before you plan around them.