Licensed ADU contractor Full Steam Ahead Construction serves East Bay homeowners with custom accessory dwelling units, including garage conversions, backyard cottages & in-law suites. Serving Concord, Oakland, Berkeley & more.
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Shed Shop offers ADUs (Accessory Dwelling Units) via their Mini Cottage program. Sizes range from 192 to 480 sq. ft. Services include foundation, plumbing, electrical, permits & more. Available in select cities.
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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 &... read more
Dream Build Services is a full-service ADU contractor in Fremont, CA, offering detached ADUs, garage conversions, basement conversions, and JADUs. Services include design, permits, electrical, plumbing, HVAC, and solar integration across the East ... read more
Vargas Construction is a California ADU contractor offering detached, attached, garage, junior, and multifamily ADUs. They handle design, permitting, and construction with energy-efficient materials, custom interiors, and full amenities in 2–6 m... read more
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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Bay Star Garage transforms garages into functional spaces in Santa Clara & Livermore, CA. Services include remodeling, flooring, EV charging, lighting, conversions & cabinets. Licensed, bonded & insured contractor specializing in ADUs ... read more
Home Quality Remodeling Inc. is a licensed Bay Area general contractor (CSLB #838832) with 20+ years of experience. Services include kitchen & bathroom remodeling, room additions, ADUs, and outdoor living across Concord, San Jose, and Paramus,... read more
Home Quality Remodeling Inc. is a licensed Bay Area general contractor (CSLB #838832) with 20+ years of experience. Services include kitchen & bathroom remodeling, room additions, ADUs, and outdoor living across California and New Jersey.
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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 wi... read more
LiveLarge Home is a California prefab ADU builder offering full-service solutions from permits to final inspection. Build times start at 4–6 weeks, with fixed pricing from $412/sq. ft. Models range from studios to 2-bed/2-bath units with premium... read more
Optivest Build is a licensed general contractor offering ADU construction, garage conversions, home additions, renovations, and new builds. They manage permits, design, and inspections, delivering residential and commercial projects on time and wi... read more
ExpandADU is a California-based prefab ADU builder offering full-service accessory dwelling unit construction, including consultation, design, planning, and build. Serving the Bay Area and beyond, they specialize in detached ADUs, granny flats, an... 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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Apex ADU Builders is a Los Angeles-based contractor specializing in accessory dwelling unit construction. Services include new builds, garage conversions, permitting, and design. Costs range from $80K–$400K, with potential ROI 35% higher than ho... 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.