Home Additions in Union City, CA
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Single-Story vs. Second-Story Additions
| Single-story addition | Second-story addition or new home |
|---|---|
| Application, 3 plan sets, 2 copies of the Title 24 energy report, 2 sets of structural calculations if applicable, CALGreen checklist, HOA letter if applicable. | 4 plan sets, a soils or geology report if applicable, and a Planning Division approval letter with annotated Conditions of Approval before building submittal. New homes also need a survey and a construction waste plan. |
Addition Work
Union City Addition Triggers
- Underground service: additions that increase floor area by 50% or more must underground the overhead service drop.
- School fees: New Haven Unified School District fees apply to additions of 500 sq ft or more; the receipt is required before the permit is issued.
- Sewer: a Union Sanitary District permit may be required.
- Grading: Public Works issues grading permits, (510) 675-5308.
- Trees: trees on residential property with a trunk circumference of 35 inches or more (70 inches combined for multiple trunks), measured 3 feet above grade, need a Public Works permit.
- Hillside: the 1995 Hillside Area Plan covers land north and east of Mission Boulevard, limits development to the area between Mission Boulevard and the Peavine, and bars development on natural slopes over 40%. The Hayward Fault follows the alignment of Mission Boulevard.
Fire sprinklers (Municipal Code 15.20.100): required for new construction, and for additions when the existing area (not counting the garage) grows by more than 50% or the total area including the garage exceeds 2,500 sq ft. Fire protection is provided by the Alameda County Fire Department.
Where to Submit
34009 Alvarado-Niles Road, Union City, CA 94587 · City Hall (510) 471-3232
Building Division (510) 675-5313 · Planning (510) 675-5379
Building counter Monday to Thursday 9 a.m. to 5 p.m. and alternate Fridays 9 a.m. to noon. Planning counter Monday to Thursday 9 a.m. to 2 p.m., with appointments given priority. Plan submittals and resubmittals are taken at the counter.
Inspections are requested through the Building Inspection Hotline, (510) 487-0711. The City caps the number of inspections per day, so call early.
Explore More
Other Union City services: ADUs · Bathrooms · Kitchens · New Homes · Union City overview
Same service nearby: Fremont · Newark · Alameda County
See home additions and second stories.
Union City Home Additions FAQ
Do second-story additions need Planning approval in Union City?
Yes. A Planning approval letter with annotated Conditions of Approval is required before the building submittal.
When does an addition require fire sprinklers in Union City?
When existing area, excluding the garage, grows by more than 50%, or total area including the garage exceeds 2,500 sq ft.
Do I have to underground my electrical service?
Yes, if the addition increases floor area by 50% or more.
Are school fees due?
New Haven Unified fees apply to additions of 500 sq ft or more.