Kaplan Architects added a 280 sq ft ADU to an existing garage in Crocker Highlands, Oakland. Built into a hillside, it features a kitchenette, full bath, and Tudor-style exterior, serving as office, studio, or rental unit.
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Parsa Construction offers residential & commercial remodeling, ADU construction, and retrofit services. Specializing in kitchen, bathroom, room additions, and accessory dwelling units like granny flats and detached ADUs, they manage permits, d... read more
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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Urban Shore Builders offers full-service ADU design & construction, including garage conversions, detached units & additions. As a turnkey ADU contractor, they handle permits, design & build. Services include plumbing, electrical, HVAC... read more
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
C.J. Skeeles General Contractor specializes in ADU construction in Hayward, Oakland & San Francisco, CA. Services include detached ADUs, garage conversions & interior conversions, all built to California zoning & permitting requirement... read more
Roof and Realm is a California-based steel-framed modular home and ADU builder offering fire, earthquake, and wind-resistant structures. Their eco-friendly builds use 98% recyclable materials, generate minimal waste, and support solar-ready, Net P... read more
DevArt8 Builders specializes in ADU construction in Gilroy, offering floor plans from 350–650 sq. ft. They handle permits, ensure zoning compliance, and build detached ADUs, attached units, and garage conversions tailored to each property.
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Hamilton Exteriors builds detached ADUs, garage conversions, and JADUs across 6 Bay Area counties. Licensed (CSLB #1078806), insured, and bonded. Projects run 5–9 months with fixed-price contracts. CalHFA grants and $0-down financing available.<... read more
Geico Builders offers ADU services including detached ADUs, attached ADUs, Junior ADUs, garage conversions, and home additions. Ideal for rental income, family housing, or maximizing space on your existing property.
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Clarity Construction is a Bay Area contractor specializing in ADUs, home additions, and remodeling in Sunnyvale, Palo Alto, and South San Francisco. Services include backyard ADU builds, in-law suites, permits, and kitchen remodels.
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Gordon Reese Design Build is a licensed ADU contractor in Walnut Creek, CA, with 41+ years of experience. They offer custom ADU design and construction, 3D renderings, transparent pricing, serving the Bay Area including Danville, Lafayette & C... read more
Type Five is a Berkeley, CA-based ADU builder offering custom backyard cottages, granny flats & in-law suites. They combine modular design, transparent pricing & streamlined construction for stress-free, high-quality detached ADUs built to... read more
Shefer Builder Inc. offers full-service ADU construction, managing design, permits, and building. Specializing in detached ADUs, granny flats, and in-law suites, they deliver custom accessory dwelling units that boost property value and rental inc... read more
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 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.