Home Remodeling, ADUs & Additions in Union City
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Our Services in Union City
Backyard ADUs, garage conversions and junior ADUsBathroom Remodeling in Union City
Primary suites, hall baths and accessible bathroomsKitchen Remodeling in Union City
Open layouts, islands, structural and system upgradesHome Additions in Union City
Single-story additions and second storiesNew Home Construction in Union City
Custom homes and teardown rebuilds
Union City General Contractor for ADUs, Additions and Remodels
Axiom Renovation (CA Lic. #1105006) builds ADUs, additions, remodels and outdoor projects in Union City. We handle design, City review, permits and construction.
Union City updated its ADU rules in March 2025 to allow up to two ADUs plus a junior ADU on a single-family lot.
What We Build in Union City
- ADUs: detached, attached and junior ADUs, plus garage conversions
- Home additions and second story additions
- New custom homes, including tear-down and rebuild
- Kitchen and bathroom remodels and whole-home renovations
- Outdoor living: pools and spas, outdoor kitchens, pavers and hardscape, and artificial turf, lawns and landscaping
See finished work in our portfolio.
Union City ADU Rules at a Glance
- A single-family lot can have up to two ADUs plus a JADU, for example a new detached ADU of 800 sq ft or less plus an ADU within existing space.
- New attached ADUs can be up to 1,000 sq ft and new detached ADUs up to 1,200 sq ft. JADUs can be up to 500 sq ft; conversions have no size limit.
- Detached ADUs are limited to 16 ft (18 ft near transit, plus 2 ft for roof pitch); attached ADUs to 30 ft or the zone limit and two stories.
- Side and rear setbacks are 4 ft, and no parking is required for an ADU or JADU.
- Rentals must be at least 30 days. New detached ADUs need solar panels or proof of existing solar on the home.
- Review is ministerial, with a decision within 60 days.
Source: Union City Municipal Code Chapter 18.34 (Ordinance 2025-002).
Rules change often, so we confirm the current standards for your parcel during the site assessment.
Other Union City Rules That Affect Your Project
- Second stories and new homes need a Planning Division approval letter before the building permit.
- Trees: on residential property, trees 35 in. or more in circumference need a permit.
- Landscaping: WELO rules apply to new landscapes of 500 sq ft or more and rehabilitated landscapes of 2,500 sq ft or more that need a permit.
- Utilities: Alameda County Water District, Union Sanitary District and PG&E all play a role in ADU projects.
Getting Permits in Union City
Union City accepts building submittals at the Building Division counter, and some over-the-counter permits by email.
We Also Work Near Union City
We also build in nearby Fremont, Newark, Pleasanton, and across the Bay Area. See all of our service areas.
Frequently Asked Questions
How many ADUs can I build in Union City?
Under the 2025 ordinance, a single-family lot can have up to two ADUs plus a junior ADU.
Does Union City require parking for an ADU?
No. Union City does not require parking for an ADU or a junior ADU.
Do new detached ADUs in Union City need solar?
Yes. New detached ADUs need solar panels or proof of existing solar on the main home.
Does a second story in Union City need planning approval?
Yes. Second-story additions and new homes need a Planning Division approval letter before the building permit.