Home Remodeling, ADUs & Additions in Alamo
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Our Services in Alamo
Backyard ADUs, garage conversions and junior ADUsBathroom Remodeling in Alamo
Primary suites, hall baths and accessible bathroomsKitchen Remodeling in Alamo
Open layouts, islands, structural and system upgradesHome Additions in Alamo
Single-story additions and second storiesNew Home Construction in Alamo
Custom homes and teardown rebuilds
Alamo General Contractor for ADUs, Additions and Remodels
Axiom Renovation (CA Lic. #1105006) builds ADUs, additions, remodels, pools and outdoor projects in Alamo. Alamo is an unincorporated community, so Contra Costa County’s Department of Conservation and Development handles both planning and building permits. Land-use matters may also go to the Alamo Municipal Advisory Council, which advises the County.
Many Alamo properties are larger lots, which opens up more room for a detached ADU, a pool or a full outdoor living space.
What We Build in Alamo
- 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.
Alamo ADU Rules at a Glance
- Under the County’s state-exempt option, a single-family lot can have a converted ADU, a converted JADU and a new detached ADU of 800 sq ft or less with 4 ft side and rear setbacks, approved ministerially.
- Detached ADUs can be up to 1,000 sq ft, or 1,200 sq ft on lots of 12,000 sq ft or more. Attached ADUs follow the same limits and are generally capped at 50% of the main home.
- A garage attached to a detached ADU can be up to 500 sq ft on lots of 20,000 sq ft or less, and larger on bigger lots.
- New-construction ADUs need 4 ft side and rear setbacks; conversions need none.
- One parking space is generally required, with exemptions (within a half mile of transit, conversions and others), and converted garages do not need replacement parking.
- Rentals shorter than 30 days are not allowed. Properties on septic need Environmental Health review.
Source: Contra Costa County Code Chapter 82-24 (Ordinance 2025-07).
Rules change often, so we confirm the current standards for your parcel during the site assessment.
Other Alamo Rules That Affect Your Project
- Pools: in-ground pools need a County building permit.
- Exempt work: under the County’s handout, fences up to 7 ft and retaining walls up to 3 ft (with no surcharge) generally do not need a building permit; masonry walls do.
- Protected trees: listed native trees such as oaks, bay, buckeye and sycamore, 20 in. in circumference or more, are protected in many settings, and work within their dripline may need a tree permit.
- Landscaping: the County follows the state Water Efficient Landscape Ordinance: 500 sq ft or more of new landscape, or 2,500 sq ft or more of rehabilitated landscape.
Getting Permits in Alamo
Applications go through Contra Costa County’s ePermits Center. For an ADU, the ADU permit application goes to the County before the building permit.
We Also Work Near Alamo
We also build in nearby Danville, Walnut Creek, San Ramon, and across the Bay Area. See all of our service areas.
Frequently Asked Questions
Who issues permits in Alamo?
Alamo is unincorporated, so Contra Costa County’s Department of Conservation and Development handles planning and building permits.
How big can an ADU be in Alamo?
A detached ADU can be up to 1,000 sq ft, or 1,200 sq ft on lots of 12,000 sq ft or more.
Do I need a permit for a pool in Alamo?
Yes. In-ground pools need a Contra Costa County building permit.
Can I build an ADU on a septic lot in Alamo?
Often yes, but properties on septic need Contra Costa Environmental Health review before the ADU can be approved.