Home Additions in Fremont, CA
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We Built an Addition in Fremont
Our Fremont home remodel and addition added space and opened the house with a vaulted living room. For a Fremont addition, design review is ministerial (staff-level) by default. It becomes discretionary, with a Zoning Administrator public hearing, if the main building would exceed 7,500 sq ft or the project does not meet the citywide design rules (FMC 18.235).
Our Fremont Remodel and Addition
Sprinklers, Hillsides and Trees
- Fire sprinklers (2025 Fire Code, Ord. 11-2025): an addition triggers whole-house sprinklers if total floor area exceeds 5,000 sq ft or the addition is 50% or more of the existing floor area. Additions under 500 sq ft, or under 1,000 sq ft with a fire alarm, can be exempt when conditions are met.
- Hillside overlay (FMC 18.130): roofs up to 30 feet above approved grade, 18 feet on hilltop ridges, decks no more than 5 feet above grade, retaining walls generally 3 feet each. The Hill Area Initiative of 2002 applies above the toe-of-hill line on larger parcels.
- Trees (FMC 18.215): 18 inches for any species, 10 inches for natives such as oak, redwood or bay. Developed R-1 lots of 10,000 sq ft or less are exempt for trees behind the front of the house, except landmark trees.
- Historic overlays: single-family homes are generally exempt unless the house is a listed or potential historic resource.
Seismic: the Hayward Fault runs through Fremont, most of the city is within a liquefaction zone, and the eastern hills have landslide hazards that require site-specific geotechnical analysis. We plan foundations and structural design accordingly.
Permits and Fees
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: ADUs · Bathrooms · Kitchens · New Homes · Fremont overview
Same service nearby: Union City · Newark · Milpitas
See our Fremont home remodel and addition project.
Fremont Home Additions FAQ
Does an addition need design review in Fremont?
Yes, but it is staff-level by default. A hearing is required if the main building would exceed 7,500 sq ft or the design does not meet citywide rules.
When does an addition require sprinklers in Fremont?
When total floor area exceeds 5,000 sq ft or the addition is 50% or more of the existing floor area, with exemptions for small additions.
Are school fees due?
Additions of 500 sq ft or less are exempt; larger ones pay Fremont Unified fees.
Have you built an addition in Fremont?
Yes. See our Fremont home remodel and addition.