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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Joy Line Homes offers the ADURA ADU Series — factory-built backyard cottages and granny flats featuring modern design, high-end finishes, and durable materials. An affordable, plan-based ADU solution for homeowners seeking quality detached accessory dwelling units.
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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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King David Construction is a Palo Alto ADU contractor offering full-service design, permitting & construction across the Bay Area. Specializing in detached ADUs, garage conversions & in-law suites.
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Remodeling Heroes is a licensed ADU contractor in the SF Bay Area offering garage conversions, detached ADUs, in-law suites, permits, and full project management for code-compliant, lot-smart accessory dwelling unit construction.
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At Ingenuity Construction Group, we specialize in crafting exceptional Accessory Dwelling Units (ADUs) that blend seamlessly with your existing property. With over 20 years of experience, our dedicated team ensures each ADU project is completed with meticulous attention to detail and superior craftsmanship.
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Whether you’re planning a rental unit, a guest house, or a private suite for family, RenoRevive will help you design and build a fully functional ADU that fits your needs, your lot, and your long-term goals.
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ENE Smarthome, Inc. is a Bay Area contractor offering home remodeling, ADU construction, smart home upgrades, and accessibility improvements. Services include garage conversions, granny flats, aging-in-place remodels, and SB9-compliant ADU projects.
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ADU Builders Group is a Bay Area family-owned ADU contractor with 21+ years of experience. They build attached, detached, converted, and junior ADUs, offering full design-build services, permitting support, a 3-year warranty, and a 10-year structural guarantee.
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The ADU Dudes is a Bay Area & Northern California ADU contractor offering ADU construction, JADUs, garage conversions, home additions & new builds. Licensed under San Andres Construction (#1081083), serving San Jose, Oakland, Fremont & more.
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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 meet all your functional needs.
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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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Done Right Builders & Remodeling is a licensed Bay Area ADU contractor (Lic#1002689) with 20+ years experience. Services include detached/attached ADUs, JADUs & garage conversions in Union City, Hayward, San Jose & Santa Clara.
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Bayside Builders Group is a licensed Bay Area ADU contractor with 25+ years of experience. Services include detached ADUs, garage conversions, and in-law suites. Serving Oakland, San Jose, San Francisco, and surrounding counties.
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.