ADU Builder in Fremont, CA
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Fremont ADU Rules (FMC ยง18.190.005)
- Attached ADU: up to 1,000 sq ft; up to 30 feet tall or the zone limit, whichever is lower.
- Detached ADU: up to 1,200 sq ft; 16 feet tall, or 18 feet near transit plus 2 feet for a matching roof pitch.
- Conversions of existing space have no size, height or setback limit, plus up to 150 sq ft for entry or exit.
- Junior ADU: up to 500 sq ft inside the house, which can include an attached garage. Owner occupancy is required only if it shares a bathroom.
- Setbacks: 4 feet side and rear; front setback matches the main house.
- No parking is required, and none needs to be replaced when a garage is converted.
- One ADU and one JADU per lot, no owner-occupancy requirement for the ADU, a separate entrance and a separate address, no rentals under 30 days, and no rooftop decks.
- Fire sprinklers are not required if the main house does not require them.
ADU and Fremont Work
Three Permits Reviewed Together
A Fremont ADU needs a Ministerial Design Review, a Building Permit and a New Address, all reviewed at the same time. ADU work must be filed separately from any work on the main house. PG&E requires a separate electric meter for the ADU.
Pre-approved plans: Fremont lists nine detached plans from six designers, about 496 to 1,000 sq ft, reviewed in 7 business days instead of 15. The owner contracts with the plan’s designer, and we build it.
Where to Apply
39550 Liberty Street, Fremont, CA 94538 · (510) 494-4443
Building & Safety (510) 494-4400 · Plans & Permits (510) 494-4460 · Planning (510) 494-4440
In person Tuesday to Thursday, 8 a.m. to 3:30 p.m. (closed noon to 1); Monday and Friday by phone and email. City Hall is at 3300 Capitol Avenue.
- Register in Fremont’s Citizen Access portal.
- Choose “Apply for a Permit,” then Planning, Building or Engineering.
- Upload plans in the City’s electronic plan review (EPR) format; files that do not meet the format are rejected.
- Staff check completeness and send an invoice for plan review; review starts once it is paid.
- Resubmit corrections online; revisions to an issued permit go in as an “Amendment.”
- Book inspections online in Citizen Access. Every permit requires a building inspection.
School fees: the City issues a Certificate of Compliance, and Fremont Unified must certify it before the permit is issued; allow about two weeks. Additions and ADUs of 500 sq ft or less are exempt.
Explore More
Other Fremont services: Bathrooms · Kitchens · Additions · New Homes · Fremont overview
Same service nearby: Union City · Newark · Milpitas
See our Fremont home remodel and addition project.
Fremont ADU FAQ
How big can an ADU be in Fremont?
Up to 1,000 sq ft attached or 1,200 sq ft detached. A junior ADU is up to 500 sq ft.
Does Fremont require parking for an ADU?
No, and garage parking does not have to be replaced.
Does Fremont have pre-approved ADU plans?
Yes, nine detached plans from six designers, reviewed in 7 business days.
Does my ADU need its own address and meter?
Yes. Fremont requires a new address, and PG&E requires a separate electric meter.