Jeff Martinez Construction Inc. builds ADUs in Oakley, CA with 27+ years of experience. Services include detached ADUs, garage conversions, permits, finishing, and landscape integration across Contra Costa County.
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RWB Construction is a Lafayette, CA-based ADU contractor serving the Bay Area. They build detached ADUs, garage conversions, granny flats & in-law suites, managing design, permitting, and construction from start to finish.
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Cupertino ADU is Silicon Valley's premier ADU builder, specializing in accessory dwelling units for rental income, intergenerational living, home offices, and eco-friendly housing solutions tailored to Cupertino homeowners.
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Rosegold Builders builds custom ADUs across the Bay Area and Los Angeles, handling permits, zoning, and construction. Services include garage conversions, backyard cottages, and rental units designed to boost property value.
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ELS Home Builders specializes in ADU design and construction across San Jose, Palo Alto & the SF Bay Area. Services include granny flats, in-law suites, garage conversions & detached ADUs for multigenerational living.
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OCA Builders is a trusted Santa Cruz general contractor specializing in ADU construction, custom homes, kitchen & bathroom remodeling, room additions, and commercial build-outs, delivering quality craftsmanship with deep local zoning expertise... read more
We Do Construction specializes in ADU garage conversions across the San Francisco Bay Area. Licensed and insured, they handle permitting, 3D planning, construction, and interior design, offering free estimates for homeowners.
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Tucan Builder is a family-owned general contractor in Redwood City, CA, serving San Mateo County. Specializing in ADU construction, room additions, kitchen remodeling, and home renovations, they bring 30+ years of combined experience.
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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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Nestadu is a full-service ADU builder offering custom site-built and prefab accessory dwelling units. Prefab models range from $115K–$317K. Custom builds start at $400/sq ft. Financing options include HELOCs, construction loans, and CA grants.read more
Intelligent Choice Builders is a licensed Bay Area ADU contractor serving Palo Alto, Cupertino, San Jose & Sunnyvale. They build detached ADUs, garage conversions, granny flats & more, managing permits, design & construction end-to-end... read more
CDU Inc. offers expert ADU construction & remodeling in the Greater Bay Area. Services include new builds, garage conversions, electrical, plumbing & custom design to boost property value & functionality.
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Tiny House Basics designs custom tiny house trailers with insulated floors, no thermal bridging, and build-ready delivery. Models range from 10–50ft, up to 12ft wide, in bumper pull or gooseneck styles. Lifetime consulting included.
read moreSan 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 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:
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.
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:
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.