ADU Pricing · 2026

How Much Does an ADU Cost in San Jose? (2026)

By Framework First· · 9 min read
How Much Does an ADU Cost in San Jose? (2026)

In San Jose, a complete, move-in-ready ADU from Framework First costs between $199,000 and $599,000. That range includes a permitting budget, plans, foundation, the factory build, delivery, utility hookups, appliances, and final inspection. Because San Jose sets its own permit fees, your exact permit cost is confirmed for your specific address in the feasibility study rather than baked into a flat statewide number.

The short version: A detached ADU in San Jose typically lands between $199,000 (our 450 sq ft studio) and $599,000 (our largest 1,200 sq ft three-bedroom). With San Jose rents among the highest in the country, a well-sized ADU often pays for a meaningful share of itself through rental income, and adds lasting value to your property.

What “all-inclusive” actually means

Most ADU price quotes you find online are missing pieces. They might cover the structure but leave out the foundation, the permit fees, the crane delivery, or the appliances. Then the real bill arrives.

We do it differently. Our price is built around a real permitting budget instead of a bare structure quote you have to pad yourself. When we quote you a number for your San Jose lot, it includes:

  • A permitting budget and permit coordination with the City of San Jose. Your exact permit fees are set by the city and confirmed in your feasibility study.
  • Architectural and engineering plans
  • The foundation and standard site work
  • The home itself, roughly 97% built in our Salinas factory
  • Crane delivery and set
  • Electrical, plumbing, and gas hookups to your home
  • Appliances
  • Final inspection and sign-off

Property-specific work like a septic upgrade or retaining wall is not part of that listed price, but we build it in-house under your contract so your project never needs a second, outside contractor. We anchor on the total, honest cost so you can plan realistically. If you want the full statewide picture, our guide on how much an ADU costs in California breaks it down further.

San Jose ADU prices by model

We build 14 models from 405 to 1,200 square feet, in three architectural styles (Classic Craftsman is standard, with Urban Farmhouse and Ultra Modern available). Here is the lineup with real, all-inclusive pricing.

ModelSizeBeds / BathsAll-Inclusive Price*Timeline
Four Fifty450 sq ftStudio / 1$199,000~4 months
The 405405 sq ft1 / 1$239,000~5 months
Five Five Five555 sq ft1 / 1$279,000~5 months
Six Sixty660 sq ft1 / 1$309,000~5 months
Six Sixty 2BR660 sq ft2 / 1$339,000~5 months
Seven Forty-Nine749 sq ft2 / 2$369,000~5-6 months
Eight Eighty-Five 2BR885 sq ft2 / 1$399,000~6 months
Nine Forty-Five 2/1945 sq ft2 / 1$419,000~6 months
Nine Forty-Five 3/1945 sq ft3 / 1$445,000~6 months
Eight Eighty-Five 2/2885 sq ft2 / 2$429,000~6 months
Nine Forty-Five 2/2945 sq ft2 / 2$449,000~6 months
Nine Forty-Five 3/2945 sq ft3 / 2$479,000~6 months
Twelve Hundred1,200 sq ft3 / 2$549,000~7-9 months
Twelve Hundred U1,200 sq ft3 / 2$599,000~7-9 months

*Includes a permitting budget, not final permit costs. Permits and property-specific site work (septic, retaining walls, etc.) vary by property and are confirmed in your feasibility study.

Our most popular home in the Bay Area is the Six Sixty, a full one-bedroom that lives much larger than its footprint. For families chasing the strongest rental return, the Six Sixty 2BR packs two bedrooms into the same compact size. You can browse all of them on our models page or get an instant estimate with the cost calculator.

Why San Jose is one of the best places in California to build an ADU

San Jose sits at the heart of Silicon Valley, where housing demand stays high and rents run well above the state average. That combination makes the math on an ADU especially compelling here.

A backyard home in San Jose gives you a few clear paths:

  • Rental income. A separate, legal one- or two-bedroom unit in San Jose commands strong monthly rent. Two bedrooms typically rent for considerably more than one, which is why the Six Sixty 2BR is our pick for income-focused owners.
  • Family housing. Many San Jose homeowners build to house aging parents or adult children who can’t afford to buy nearby. You keep family close while everyone keeps their independence.
  • Property value. A permitted, professionally built ADU adds real, appraisable square footage to your lot. In a high-value market like San Jose, that lift can be significant.

San Jose has also been one of California’s more ADU-friendly cities, with pre-approved plan programs and streamlined review. State law backs you up here too. Approval is ministerial, meaning the city must approve a complete, compliant application within 60 days, with no discretionary hearing and no neighbors voting on your project. For the full rundown of your rights, see our guide to California ADU laws in 2026.

Estimating your San Jose ADU’s return

Every lot and every owner is different, so treat the following as a simple framework rather than a promise. The idea is to compare your monthly mortgage cost against realistic local rent.

FactorWhat to consider
Build costYour chosen model’s all-inclusive price, $199K to $599K
FinancingMany owners use a HELOC, cash-out refinance, or renovation loan
Monthly rentSan Jose one- and two-bedroom rents are among the highest in the U.S.
Net cash flowMonthly rent minus your monthly loan payment
Property valueAppraisable square footage added to your home

For most San Jose owners, the rent on a one- or two-bedroom ADU covers a substantial portion of the financing payment, sometimes most of it. Over time, as rents rise and the loan is paid down, the unit shifts from breaking even to generating real income, on top of the equity you’ve added. If you’re weighing how to pay for it, our guides on financing an ADU in California and financing without cash on hand walk through the common routes.

To see real-world rent ranges and how they map to each model, read how much rent an ADU can earn in California.

What can change your final San Jose price

Our model prices include a permitting budget and are genuinely comprehensive, but a few site-specific factors can nudge your total. We confirm every one of these for free in a feasibility study before you commit a dollar:

  • Site access. Crane reach and a clear path for delivery. Tight or sloped lots may need extra planning.
  • Utility distance. How far your existing electrical, water, sewer, and gas lines sit from the build location.
  • Soil and grading. Some San Jose lots need additional site prep or specific foundation work.
  • Local fees. San Jose’s permit and impact fees vary, and ADUs under 750 sq ft are exempt from impact fees under state law. Anything above 750 sq ft is charged proportionally. We confirm exact figures for your address in the study.

We’d rather tell you the honest number up front than surprise you later. That is the whole point of the feasibility study.

Frequently asked questions

How much does an ADU cost in San Jose?

With Framework First, a complete ADU in San Jose costs between $199,000 and $599,000. That range includes a permitting budget, plans, foundation, the factory-built home, delivery, hookups, appliances, and inspection, with your exact permit cost confirmed against the city’s fee schedule during your feasibility study. The price depends on which of our 14 models you choose, from a 450 sq ft studio to a 1,200 sq ft three-bedroom.

Is building an ADU in San Jose worth it?

For most owners, yes. San Jose has some of the highest rents in the country, so a one- or two-bedroom ADU can cover much of its financing cost while adding permanent, appraisable value to your property. The exact return depends on your model, your financing, and local rent, which is why we run the numbers with you before you commit.

How long does it take to build an ADU in San Jose?

Our homes take roughly 4 to 9 months depending on the model, since about 97% of the build happens in our Salinas factory while your site and permits are prepared in parallel. That is much faster than typical site-built construction. See how long it takes to build an ADU for the full breakdown.

Do I need to live on the property to rent out my San Jose ADU?

No. Owner-occupancy is permanently removed for standard ADUs under California law, so you can rent out your ADU without living on-site. The one exception is a JADU (a junior ADU up to 500 sq ft within your home’s existing walls), which still requires owner-occupancy. Our JADU vs ADU guide explains the difference.

How many ADUs can I build on my San Jose lot?

A single-family lot in California may have the primary home plus one ADU and one JADU. If you’re unsure what your specific lot allows, our guide on whether you can build an ADU on your property and your feasibility study will give you a clear answer.

Ready to see your San Jose number?

The fastest way to know exactly what an ADU will cost on your lot is our feasibility study. Our team confirms your setbacks, utility distances, local fees, and the right model for your goals, with no pressure and no obligation.

Start your feasibility study and we’ll give you a real, all-inclusive number for your San Jose property. You can also explore what’s possible in your area on our San Jose page or check current pricing across the full lineup.

Form not loading? Open it directly →

Talk to a Real Person

Have a question this didn't answer?

Tell us a bit about your property below, and one of our Account Managers will follow up with a straight answer, not a form letter. Or call (831) 432-7721 directly.

  • A shortlist of which models actually fit your lot
  • Honest flags on anything property-specific, like slope or septic
  • A clear next step, whether that is a factory tour or a feasibility study
  • No pressure, and no obligation

Building more than one? If you're a real estate developer or investor planning multiple units, let us know in the form. We offer better pricing at volume.

“My first telephone conversation with Cathy (Owner) was one of the best, positive and kind discussions. She was thinking outside of the box and provided a possible solution like a family member. Thank you.”

Vijay Kumar

on Google