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. 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 & bey... read more
Home Revive Builders is a licensed ADU contractor in the Bay Area, CA, specializing in garage conversions, detached ADUs, in-law suites, and more. Full-service projects include design, permits, plumbing, electrical, and finishing.
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We guide you through design options and material choices, taking precise measurements to create a custom plan that perfectly fits your property. This careful planning ensures that your new ADU will seamlessly blend with your existing space and mee... read more
Urban Building Workshop is a full-service architecture firm in the Bay Area specializing in custom homes, remodels, and ADUs. Experts in Marin County, San Francisco, and Sonoma County permitting, they deliver efficient, light-filled designs.
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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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E&E General Construction Inc (License #1067263) specializes in ADU construction and garage conversions in Richmond, CA. Services include detached ADUs, attached units, and garage conversions across the Bay Area. Free estimates available.
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California Building and Remodeling offers ADU construction, kitchen & bathroom remodeling, roofing, and concrete services in Albany, CA and the Bay Area. Experienced ADU contractor serving Albany, Berkeley, Richmond & more.
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Barcci Builders specializes in ADU construction across the Bay Area, offering design, permitting, and build services. With 40+ completed units, they handle JADUs, garage conversions, attached, and detached ADUs, with costs ranging from $60K to $40... read more
Bay Area design-build ADU specialists. One project, one point of contact — design, engineering, permitting, and construction from start to finish. CSLB #1130783.
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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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Acton ADU is a Bay Area ADU contractor founded by Stan Acton with 30+ years of experience. They offer full-service ADU design, construction, garage conversions, and permitting across San Jose and the broader Bay Area.
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Atra Construction is a Bay Area ADU contractor offering full-service design and build. They handle permits, planning, and construction management. Floor plans range from 240 sq ft studios to 1,200 sq ft three-bedroom units.
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GADI Construction, led by Nadav, specializes in ADU construction, home expansions, garage conversions & granny flats. Known for detailed planning, clear communication & professional client guidance throughout every project phase.
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.