Prefab ADUs in Fremont
Fremont homeowners more than doubled ADU permits in two years — and the City charges no impact fees on ADUs of any size. 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, setbacks, utilities · reply with a fixed price
Licensed builder · Our own factory in Lathrop, CA
Real homes we build, start to finish
Quick answer
ADUs in Fremont — key facts for 2026
Most Fremont homeowners can add a detached ADU of up to 1,200 sq ft with no parking and no city impact fees at any size. 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 Fremont?
- Yes, on most single-family lots. Fremont allows a detached ADU up to 1,200 sq ft and 16 ft tall with 4-ft side and rear setbacks, plus one JADU.
- How long does a Fremont ADU permit take?
- A ministerial design review and the building permit can be reviewed at the same time; state law requires a decision within 60 days of a complete application.
- What fees does Fremont charge?
- No city development impact fees on ADUs of any size — only permit fees. Fremont Unified's school fee ($5.38 per sq ft) applies only to ADUs over 500 sq ft.
- How much does a prefab ADU cost in Fremont?
- Bay Modular: $124,900–$271,900 all-in, the same price as anywhere in California, permits and installation included.
- How many ADUs does Fremont build?
- 188 ADU permits in 2025 — about one in three new homes permitted in the city, up from 84 in 2023.
- What does an ADU rent for in Fremont?
- Average asking rent in Fremont was $3,375 a month in August 2026 (Zillow), up 26% since January 2021.
Sources: HCD APR 2025, Fremont Municipal Code 18.190.005 and the City’s ADU Informational Handout (Jan 2026), Fremont Unified developer fees (May 2026), Zillow ZORI Aug 2026. Last reviewed October 2026.
Fremont in numbers
A third of Fremont’s new homes are ADUs
ADU permits more than doubled from 84 in 2023 to 188 in 2025 — about one in three new homes permitted in Fremont last year was an ADU.
ADU permits issued in the City of Fremont
Source: California HCD Annual Progress Report data (Table A2), City of Fremont, permits issued per year. Percent = ADUs among all housing units permitted in the city that year.
average Fremont asking rent since January 2021 ($2,681 → $3,375)
Zillow Observed Rent Index, City of Fremont, Aug 2026more ADU permits in 2025 than in 2023 (84 → 188)
HCD APR data, 2023–2025Can I build in Fremont?
Most Fremont lots with a house can add an ADU
Fremont’s ADU rules (Municipal Code 18.190.005) follow state law with a few local details. Here is what matters for most homeowners:
A detached ADU can be up to 1,200 sq ft, with no limit on bedrooms. All our models fit.
4 ft from side and rear lot lines; 16 ft tall (18 ft near major transit, plus 2 ft for a roof that matches the house).
A ministerial design review and a building permit — reviewed at the same time if you ask for concurrent review.
No parking required for an ADU, and a garage you convert or remove doesn't need replacing.
One ADU and one JADU on a single-family lot. ADUs don't count toward lot coverage.
About 10 ft from the main house and 5 ft from the lot line under the building code; PG&E requires a separate electric meter.
Based on Fremont Municipal Code 18.190.005 (Ord. 06-2023) and the City’s ADU Informational Handout (updated Jan 5, 2026). 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 Fremont
What an ADU costs in Fremont
Same all-in price as anywhere in California. Our models are all under 750 sq ft, and Fremont charges no city impact fees at any size — four of five pay no school fees either.
| 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: City of Fremont ADU Informational Handout (Jan 2026, FAQ 4); Fremont Unified School District developer fees (effective May 24, 2026); Ed. Code §17620. Launch pricing runs through December 31, 2026. Comparison is general — every project differs.
Renting in Fremont
Renting out an ADU in Fremont
average asking rent for all homes in Fremont — up 5% in a year, 26% since 2021. HUD's 2027 fair rent for a 1-bedroom in the area is $2,290.
Zillow Observed Rent Index, City of Fremont, Aug 2026 · HUD FY2027 FMR ADU for rental incomeFremont ADUs and JADUs can't be rented for less than 30 days — plan on long-term tenants.
No owner-occupancy rule for an ADU — only for a JADU that shares a bathroom with the main house.
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: City of Fremont ADU Informational Handout (Jan 2026); Civil Code §1947.12. Comparison: HUD FY2027 2-bedroom Fair Market Rent, Oakland-Fremont area ($2,805) × 12 ÷ $271,900; U.S. Treasury (Oct 6, 2026); FTSE Nareit (Sep 2026); Zillow ZORI ÷ ZHVI, San Francisco–Oakland metro (Aug 2026); FDIC (Sep 2026). Not legal or investment advice.
Permits in Fremont
How your Fremont permit works — we handle it
Free lot check
Zoning, setbacks, building separation, sewer, water and power for your Fremont address.
Plans & submittal
Our HCD-approved plans plus your site plan, filed online as a ministerial design review and building permit together.
City review
Planning and Building review at the same time (concurrent review); we answer comments and arrange a new address.
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 City’s ADU Informational Handout (Jan 2026) and Gov. Code §66317. Fremont also runs a preapproved ADU plans program with faster review and lower permit costs.
Why now
Start your Fremont 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.
Fremont ADU questions
Read our ADU guides, see all of California, or call (209) 214-6845.
Can I build an ADU on my lot in Fremont?
Most Fremont single-family lots can add a detached ADU of up to 1,200 sq ft and 16 ft tall, with 4-foot side and rear setbacks, plus one JADU inside the house. We check your address for free.
How much does an ADU cost in Fremont?
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. Fremont charges no city impact fees on ADUs, and school fees only above 500 sq ft.
How long does an ADU permit take in Fremont?
Fremont reviews the ministerial design review and building permit together, 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 Fremont?
No. Fremont requires no parking for an ADU, and a garage you convert or remove doesn't need replacing.
Can I rent my Fremont ADU on Airbnb?
No. Fremont ADUs and JADUs can't be rented for terms shorter than 30 days.
Do I have to live on the property?
No. Fremont has no owner-occupancy rule for ADUs; it applies only to a JADU that shares a bathroom with the main house.
Does an ADU in Fremont need its own utilities?
PG&E requires a separate electric meter for an ADU; water (ACWD) and sewer (Union Sanitary District) may charge connection fees. We include utility work in your lot-specific quote.
Is an ADU a better investment than a rental property in Fremont?
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 in the Oakland-Fremont area ($2,805) earns about 12.5% a year on its price before costs, vs. about 3.6% for a typical Bay Area rental home (Zillow, Aug 2026). Not investment advice.
Free · no obligation
Can you build an ADU on your Fremont lot?
Send your Fremont address. We'll check zoning, setbacks, separation and utilities, 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 Fremont, 2021–2025, updated Oct 2026); Zillow Observed Rent Index, City of Fremont (Aug 2026); HUD FY2027 Fair Market Rents; Fremont Municipal Code 18.190.005; City of Fremont ADU Informational Handout (Jan 2026); Fremont Unified School District developer fees (May 2026). Prices: Bay Modular, October 2026. Not legal advice.