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
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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DNM Architecture is a California-based firm specializing in ADU design and permitting. Their ADUxDNM program covers site analysis, design, permitting, and construction management, offering detached ADUs, garage conversions, and 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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Edri Construction, Inc. in Burlingame offers full-service ADU construction across the Bay Area, including garage conversions, detached ADUs, attached additions, and custom interiors, with energy-efficient builds and multi-generational living solut... read more
Mountain Top Construction is a Bay Area ADU builder serving San Rafael, San Francisco, and Las Vegas. They specialize in detached ADUs, backyard cottages, granny flats, and in-law suites, managing design, permitting, and construction.
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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
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
Decor Builders is a San Jose-based ADU contractor with 15+ years of Bay Area experience. They offer full-service ADU design and construction, including granny flats and in-law suites, handling permits, engineering, and project management.
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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 acces... read more
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 project... read more
Green Bay Remodeling offers ADU construction in Palo Alto, CA, including detached units, garage conversions, basement units & JADUs. ADUs boost property value, generate rental income & support multigenerational living.
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Bay Builders & Remodeling specializes in custom ADU construction across Santa Clara, San Mateo, and East Bay. Services include attached, detached, garage conversions, and JADUs, helping homeowners add rental income, family housing, or workspac... 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.