ADU Contractors near San Mateo, CA
亞華建築YAHUA CONSTRUCTION
650Bfremont Ave, Los Altos, CA 94024
16 miles
YAHUA Construction Inc. is a California-based licensed general contractor with 20+ years of experience. Specializing in ADUs, remodeling, MEP, roofing, and more, they serve the Bay Area with quality, sustainable construction.
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Clever Design & Remodeling
1630 Oakland Road, San Jose, CA 95131
25.8 miles
Clever Design & Remodeling builds ADUs across the San Francisco Bay Area, including garage conversions, attached, detached, and junior ADUs. Services cover permits, construction, interior design, and landscaping. Average ADU cost is ~$145,000.... read more
Smith and Son Construction
1771 Vineyard Drive, Antioch, CA 94509
42.7 miles
At Smith and Son Construction, they specialize in designing and building high-quality ADUs in San Leandro, CA. Whether you envision a private guest house, a rental unit, or a home office, they deliver innovative designs, expert craftsmanship, and ... read more
Eco Scale Construction
Sunnyvale, CA 94085
19.9 miles
Eco Scale Construction builds ADUs in Sunnyvale, Los Altos & Palo Alto, CA. Services include detached ADUs, garage conversions & JADUs. Costs range from $80K–$400K+. Fully compliant with California ADU regulations.
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Wellmade
2371 Verna Court, San Leandro, CA 94577
13.1 miles
Wellmade is a California prefab ADU builder specializing in panelized accessory dwelling units. Founded in 2020, they've completed 200+ projects, reducing construction waste by 85%. Serving CA, OR, and WA with all-inclusive pricing.
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Burton Builders LLC
32 9th Street, Richmond, CA 94801
26.4 miles
Burton Builders LLC is a trusted construction company specializing in ADU construction, single-family, multifamily, and commercial builds. Known for quality workmanship and client-focused service, they deliver expert results on every project.
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LRL Builders
1661 Botelho Drive, Walnut Creek, CA 94596
27.3 miles
OT Bay Builders
1580 Oakland Road, San Jose, CA 95131
25.8 miles
OT Bay Builders is a complete remodeling company with over 40 years of combined experience amongst our team. We’re expert Bay Area ADU builders in San Jose with a customer-first mindset. As a full-service ADU builder, you can trust us to remain ... read more
Second Dwellings
100 Higgins Canyon Road, Half Moon Bay, CA 94019
9.1 miles
Jaws Construction Services
14000 Kelso Road, Byron, CA 94514
43.3 miles
Jaws Construction Services builds ADUs, garage conversions, and JADUs. They handle permits, HOA coordination, and offer site-built or prefab options. East Bay ADUs rent for $1,500–$3,500+/month, potentially boosting property value.
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Mission Home Remodeling
475 Gough Street, San Francisco, CA 94102
16.7 miles
ADU Builders Bay Area
111 N Market St Suite 1150, San Jose, CA 95113
26 miles
ADU Builders Bay Area specializes in detached ADUs, garage conversions, in-law suites & more. Expert ADU contractors offering transparent pricing, full permitting & quality construction throughout the Bay Area.
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ADBC Architecture
460 Mandana Boulevard, Oakland, CA 94610
18.5 miles
ADBC Architecture completed an 800 SF detached ADU in East Bay, CA in 2025, designed for multigenerational living. Built with thermally modified wood and steel, the backyard cottage features high ceilings and large windows for a spacious feel.
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Santa Cruz Construction Experts
303 Potrero Street, Santa Cruz, CA 95060
42.3 miles
Santa Cruz Construction Experts builds ADUs in Scotts Valley, CA, including detached units, granny flats & in-law suites. They also construct pool houses, garages & outdoor spaces, ensuring local code compliance.
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New Avenue, Inc
2120 University Avenue, Berkeley, CA 94704
22.2 miles
New Avenue, Inc is a full-service design-build company serving the San Francisco Bay Area and Portland, OR since 2011. They specialize in ADUs, custom homes, renovations, additions, and Enclaves, managing design, permitting, and construction under... read more
Other cities in California
What you need to know
ADU Contractors in San Mateo: Building in One of the Bay Area's Most Sought-After Cities
San Mateo, California, sits at the heart of the San Francisco Peninsula, making it one of the most desirable — and expensive — housing markets in the nation. With median home prices consistently among the highest in the country, homeowners in San Mateo are increasingly turning to Accessory Dwelling Units (ADUs) as a smart way to add rental income, house family members, or increase property value. Finding experienced ADU contractors in San Mateo is the critical first step toward making this investment a reality.
San Mateo ADU Regulations and Permitting Requirements
San Mateo operates under both California state ADU law and its own local municipal code. The City of San Mateo has worked to align with state mandates that streamline ADU approvals, but there are still important local considerations every homeowner must understand before breaking ground:
- Maximum ADU size: Detached ADUs can be up to 1,200 square feet, while attached ADUs are generally limited to 50% of the primary dwelling's square footage.
- Setback requirements: A minimum 4-foot rear and side setback is typically required for new detached ADUs.
- Height limits: Detached ADUs are generally limited to 16 feet in height, though this can vary by zone.
- Owner-occupancy rules: California state law has suspended owner-occupancy requirements for ADUs through 2025, giving San Mateo homeowners more flexibility.
- Parking: In many cases, ADUs in San Mateo do not require additional parking spaces, especially when located near transit corridors.
Why You Need a Local ADU Contractor in San Mateo
Working with a licensed ADU contractor familiar with San Mateo's building department is essential. The city's permitting process involves plan checks, inspections, and compliance with the California Building Code, Title 24 energy standards, and local zoning ordinances. An experienced local contractor will know how to navigate the San Mateo Community Development Department, helping to avoid costly delays and revisions.
Types of ADUs Popular in San Mateo
Given the variety of lot sizes and home styles across San Mateo neighborhoods — from the flat streets near downtown to hillside properties in areas like Sugarloaf — ADU contractors in San Mateo commonly build several types of units:
- Detached ADUs: Standalone structures in the backyard, ideal for larger lots.
- Attached ADUs: Extensions of the existing home, sharing at least one wall.
- Garage Conversions: Transforming an existing garage into a livable unit, a popular and cost-effective option.
- Junior ADUs (JADUs): Units up to 500 square feet created within the existing home's footprint.
Choosing the Right ADU Contractor in San Mateo
When selecting an ADU contractor in San Mateo, CA, look for professionals who are licensed by the California Contractors State License Board (CSLB), carry proper insurance, and have a proven portfolio of completed ADU projects in the Bay Area. Request detailed bids, check references, and confirm familiarity with San Mateo's specific permitting timelines. A qualified contractor will guide you from design and permitting through construction and final inspection, ensuring your ADU is built safely, legally, and on budget.