ADU Contractors near San Mateo, CA
DSA Architects
1107 Virginia Street, Berkeley, CA 94702
22.3 miles
DSA Architects designed an 850 sq. ft. second-floor ADU in Berkeley Hills for multi-generational living. Features 2 beds, 1 bath, open layout, Tilden Park views, roof deck, solar PV, heat pumps, and gray-water system.
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Valley Home Builders inc.
3466 Edward Avenue, Santa Clara, CA 95054
24.8 miles
Valley Home Builders Inc. is a Silicon Valley design-build contractor serving Santa Clara & San Mateo Counties. Founded in 2005, they specialize in kitchen remodeling, ADU construction, and home renovations across San Jose, San Mateo & beyond.
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Element Home Remodeling
800 West El Camino Real, Mountain View, CA 94040
17 miles
Element Home Remodeling is a Mountain View ADU contractor offering full design-build services in Silicon Valley. They specialize in garage conversions, backyard cottages, in-law suites & rental units, serving Palo Alto, Sunnyvale & San Jose.
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LRL Builders
1661 Botelho Drive, Walnut Creek, CA 94596
27.3 miles
ASL Remodeling
690 Saratoga Avenue, San Jose, CA 95129
24.6 miles
ASL Remodeling is a California licensed ADU contractor (CSLB #1060310) with 20+ years experience and 300+ completed projects. Services include detached ADUs, garage conversions, granny flats, JADUs, and in-law suites with full design-build support.
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Edri Construction, Inc. San Francisco
701 Cortland Avenue, San Francisco, CA 94110
14.1 miles
Edri Construction, Inc. is a San Francisco-based ADU contractor offering full-service accessory dwelling unit construction across the Bay Area, including garage conversions, detached ADUs, granny flats, and energy-efficient home additions with in-house project management.
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Green Living Builders, LLC
833 Bancroft Way, Berkeley, CA 94710
21.5 miles
Green Living Builders LLC is a licensed, bonded Berkeley CA general contractor specializing in ADU construction, garage conversions, home remodels, and new builds across the East Bay. Diamond Certified with deep local expertise.
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Karl Kardel Company
4926 East 12th Street, Oakland, CA 94601
15.9 miles
Karl Kardel Company offers home remodeling, additions, and ADU construction in Oakland, Pasadena, and the Bay Area. Services include detached ADUs, garage conversions, granny flats, kitchen and bathroom renovations for residential properties.
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Anura Design
367 Civic Drive, Pleasant Hill, CA 94523
32.1 miles
Anura Design specializes in ADU design, offering styles from modern farmhouse and contemporary steel to Mediterranean stucco. Their interiors feature open-concept layouts, natural wood tones, and refined finishes tailored to compact, functional living spaces.
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HDR Remodeling
5677 Horton Street, Emeryville, CA 94608
19.9 miles
HDR Remodeling is a Bay Area Design Build firm since 1987, specializing in kitchen remodels, bathroom renovations, and home improvements across Oakland, Berkeley, Alameda, and the East Bay, backed by an experienced team of architects and designers.
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SOD Home Group
367 Santana Hts, San Jose, CA 95128
25.6 miles
SOD Home Group builds attached & detached ADUs, including granny flats, in-law suites, garage conversions & backyard cottages. Licensed ADU contractor (Lic. 942085) helping homeowners expand living space efficiently.
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San Francisco ADU Solutions
967 Connecticut Street, San Francisco, CA 94107
16.6 miles
ADUs (accessory dwelling units) are self-contained homes on existing properties. California's 2020 laws simplified ADU permits statewide. Alpha ADU Solutions, a San Francisco-based ADU builder with 100+ team members, specializes in granny flats, garage conversions & in-law suites.
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ProStruct Engineering
450 Folsom Street, #1502, San Francisco, CA 94105
17.2 miles
ProStruct Engineering offers ADU structural engineering services across California, providing permit-ready plans and calculations for detached ADUs, garage conversions, granny flats, and more, with a 2–3 week turnaround.
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Alameda Tiny Homes
2315 Lincoln Avenue, Alameda, CA 94501
15.3 miles
Greenwood Custom Builders, Inc.
765 Old County Road, San Carlos, CA 94070
4.9 miles
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.