Prefab ADUs in Santa Clara
Santa Clara homeowners filed 2.6 times more ADU permits in 2025 than in 2023 — and rents here are among the highest in California. We deliver an all-in prefab ADU from our factory in Lathrop — permits, foundation, delivery and installation included — at one fixed price.
Free lot check · zoning, lot size, easements · reply with a fixed price
Licensed builder · Our own factory in Lathrop, CA
Real homes we build, start to finish
Quick answer
ADUs in Santa Clara — key facts for 2026
Most Santa Clara homeowners can add a detached ADU of up to 1,000 sq ft — 1,200 sq ft on lots over 5,500 sq ft — with a building permit only, no parking and no impact fees under 750 sq ft. Bay Modular delivers a factory-built ADU all-in for $124,900–$271,900 — the same price anywhere in California.
- Can I build an ADU in Santa Clara?
- Yes, on most lots with a house. Santa Clara allows a detached ADU up to 1,000 sq ft (1,200 sq ft on lots over 5,500 sq ft) with 4-ft side and rear setbacks, approved with a building permit only.
- How long does a Santa Clara ADU permit take?
- ADUs that meet the standards are approved ministerially with a building permit; state law requires a decision within 60 days of a complete application.
- What fees does Santa Clara charge?
- No impact fees under 750 sq ft (state law). Santa Clara Unified's school fee ($5.38 per sq ft since Aug 24, 2026) applies only to ADUs over 500 sq ft.
- How much does a prefab ADU cost in Santa Clara?
- Bay Modular: $124,900–$271,900 all-in, the same price as anywhere in California, permits and installation included.
- How many ADUs does Santa Clara build?
- 140 ADU permits in 2025 — about one in four new homes permitted in the city, up from 54 in 2023.
- What does an ADU rent for in Santa Clara?
- Average asking rent in Santa Clara was $3,957 a month in August 2026 (Zillow), up 39% since January 2021.
Sources: HCD APR 2025, Santa Clara City Code 18.60.020 and Planning Division ADU handout (Rev. 01/26), Santa Clara USD developer fees (Aug 2026), Zillow ZORI Aug 2026. Last reviewed October 2026.
Santa Clara in numbers
Santa Clara’s ADU boom has just started
ADU permits jumped from 54 in 2023 to 140 in 2025 — about one in four new homes permitted in Santa Clara last year was an ADU.
ADU permits issued in the City of Santa Clara
Source: California HCD Annual Progress Report data (Table A2), City of Santa Clara, permits issued per year. Percent = ADUs among all housing units permitted in the city that year.
average Santa Clara asking rent since January 2021 ($2,841 → $3,957)
Zillow Observed Rent Index, City of Santa Clara, Aug 2026more ADU permits in 2025 than in 2023 (54 → 140)
HCD APR data, 2023–2025Can I build in Santa Clara?
Most Santa Clara lots with a house can add an ADU
Santa Clara’s ADU rules (City Code 18.60.020) follow state law with a few local details. Here is what matters for most homeowners:
A detached ADU can be up to 1,000 sq ft on lots up to 5,500 sq ft, and 1,200 sq ft on larger lots. All our models fit.
4 ft from side, rear and corner-side lot lines, 6 ft from the main house; 18 ft for a single story (25 ft for 1.5 stories).
ADUs that meet the standards are approved ministerially with a building permit — no planning hearing. No minimum lot size.
No parking required for an ADU, and a garage you convert or remove doesn't need replacing.
One detached ADU, one attached or converted ADU and one JADU on a single-family lot.
Not in an easement or the sight-distance triangle at a driveway or intersection. Historic-register properties need an extra permit.
Based on Santa Clara City Code 18.60.020 and the Planning Division’s ADU handout (Rev. 01/26). Not legal advice — rules depend on your exact lot. More in our ADU guides.
New in 2027: under AB 956 (Chapter 791, Statutes of 2026), from January 1, 2027 state law lets you build two detached ADUs on a lot with a single-family home, and HOA rules can’t block an ADU on a lot zoned to allow one.
Costs & fees in Santa Clara
What an ADU costs in Santa Clara
Same all-in price as anywhere in California. Our models are all under 750 sq ft, so none pays impact fees — and four of five pay no school fees.
| Model | All-in price | School fees | City impact fees |
|---|---|---|---|
| Backyard Studio120 sq ft · home office or guest studio, not a rentable ADU | $75,900 | $0 | $0 |
| Small Studio256 sq ft | $124,900 | $0 | $0 |
| Large Studio ADU320 sq ft | $154,900 | $0 | $0 |
| 1 Bedroom ADU480 sq ft | $214,900 | $0 | $0 |
| 2 Bedroom ADU640 sq ft | $271,900 | $3,443 | $0 |
Sources: Santa Clara Unified School District developer fees (Board approval June 25, 2026; effective Aug 24, 2026); Gov. Code §66311.5; Ed. Code §17620. Launch pricing runs through December 31, 2026. Comparison is general — every project differs.
Renting in Santa Clara
Renting out an ADU in Santa Clara
average asking rent for all homes in Santa Clara — up 7% in a year, 39% since 2021. HUD's 2027 fair rent for a 1-bedroom in the area is $2,778.
Zillow Observed Rent Index, City of Santa Clara, Aug 2026 · HUD FY2027 FMR ADU for rental incomeSanta Clara has no owner-occupancy rule for an ADU — only for a JADU that shares a bathroom with the main house.
A JADU can't be rented for less than 30 days and needs a recorded deed restriction. Plan an ADU for long-term tenants.
A new ADU is exempt from California's statewide rent cap (AB 1482) for 15 years after its certificate of occupancy.
Same money, other options
Yearly income per dollar, before taxes and costs. An ADU wins because you already own the land. Full comparison →
Sources: Santa Clara Planning Division ADU handout (Rev. 01/26); Civil Code §1947.12. Comparison: HUD FY2027 2-bedroom Fair Market Rent, San Jose-Sunnyvale-Santa Clara area ($3,272) × 12 ÷ $271,900; U.S. Treasury (Oct 6, 2026); FTSE Nareit (Sep 2026); Zillow ZORI ÷ ZHVI, San Jose metro (Aug 2026); FDIC (Sep 2026). Not legal or investment advice.
Permits in Santa Clara
How your Santa Clara permit works — we handle it
Free lot check
Zoning, lot size, easements, sight lines, sewer and power for your Santa Clara address.
Plans & submittal
Our HCD-approved plans plus your site plan, submitted as a building permit — no planning application for a standard ADU.
City review
Building Division plan check. A second-story attached ADU that doesn't match the house height would need Architectural Review — ours are single-story.
Decision in 60 days
State law requires a decision on a complete ADU application within 60 days. Your ADU is built in our factory meanwhile.
Install & move in
Delivered from our Lathrop factory, installed in about a week, inspected, then your Certificate of Occupancy.
Based on the Planning Division’s ADU handout (Rev. 01/26), the City’s permit-process page and Gov. Code §66317. Santa Clara also runs a pre-approved ADU plans program (AB 1332).
Why now
Start your Santa Clara ADU with zero risk
Lock in launch pricing, see exactly what you get, and only decide once you have a fixed price for your lot.
All-in from $75,900 — everything included
- Backyard Studio (home office)$75,900All-in · fixed in writing
- Small Studio$124,900All-in · fixed in writing
- Large Studio ADU$154,900All-in · fixed in writing
- 1 Bedroom ADU$214,900All-in · fixed in writing
- 2 Bedroom ADU$271,900All-in · fixed in writing
Zero-risk start
- Free lot check & quoteNo obligation, no credit card.
- One fixed all-in priceDesign, permits, delivery and install — one number.
- HCD-approved plansState approval #1585366, financed and appraised like a home.
- 2-year warrantyOn materials and workmanship.
Visit our factory in Lathrop, CA and walk through a finished ADU.
Santa Clara ADU questions
Read our ADU guides, see all of California, or call (209) 214-6845.
Can I build an ADU on my lot in Santa Clara?
Most Santa Clara lots with a house can add an ADU. The City allows a detached ADU up to 1,000 sq ft — 1,200 sq ft on lots over 5,500 sq ft — with 4-foot side and rear setbacks, plus an attached or converted ADU and a JADU. We check your address for free.
How much does an ADU cost in Santa Clara?
Our all-in prices are the same as anywhere in California: from $124,900 for a Small Studio to $271,900 for a 2 Bedroom ADU, with launch pricing through December 31, 2026. There are no impact fees under 750 sq ft, and school fees only above 500 sq ft.
How long does an ADU permit take in Santa Clara?
A standard ADU is approved with a building permit only, and state law requires a decision within 60 days of a complete application. Your ADU is built in our factory at the same time, so most projects take 4–6 months from signing to keys.
Do I need parking for an ADU in Santa Clara?
No. Santa Clara requires no parking for ADUs or JADUs, and a garage you convert or remove doesn't need replacing.
How tall can a detached ADU be in Santa Clara?
Up to 18 feet for a single story, or 25 feet for 1.5 stories (with a 15-foot rear setback for the upper part). Our ADUs are single-story.
Do I have to live on the property?
No. Santa Clara has no owner-occupancy rule for ADUs; it applies only to a JADU that shares a bathroom with the main house.
What school fees apply to an ADU in Santa Clara?
Santa Clara Unified charges $5.38 per sq ft from August 24, 2026, but only for ADUs over 500 sq ft. Our Backyard Studio, Small Studio, Large Studio and 1 Bedroom ADU pay none.
Is an ADU a better investment than a rental property in Santa Clara?
For most homeowners with room on their lot, yes: you don't buy land. A 2 Bedroom ADU at HUD's 2027 fair rent for a 2-bedroom ($3,272) earns about 14.5% a year on its price before costs, vs. about 3% for a typical San Jose-area rental home (Zillow, Aug 2026). Not investment advice.
Free · no obligation
Can you build an ADU on your Santa Clara lot?
Send your Santa Clara address. We'll check zoning, lot size, easements and setbacks, and send a fixed all-in price — permits included.
HCD-approved plans (#1585366) · 2-year warranty · factory in Lathrop, CA
Sources: California HCD Annual Progress Report data, Table A2 (City of Santa Clara, 2021–2025, updated Oct 2026); Zillow Observed Rent Index, City of Santa Clara (Aug 2026); HUD FY2027 Fair Market Rents; Santa Clara City Code 18.60.020; Planning Division ADU & JADU handout (Rev. 01/26); Santa Clara Unified School District developer fees (Aug 2026). Prices: Bay Modular, October 2026. Not legal advice.