ADU Contractors near San Mateo, CA

New Key Construction

2890 North Main Street, Walnut Creek, CA 94597 29.2 miles

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Bay Area Home Remodelers

225 Schwerin Street, San Francisco, CA 94134 12.2 miles

Luxury Builds

Bay Area Home Remodelers builds ADUs in Daly City, San Francisco & San Jose. Services include garage conversions, granny flats, JADUs & detached units. Full project support from permits to completion.

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SF Bay ADU

111 North Market Street, San Jose, CA 95113 27.3 miles

Licensed 25 years in business

SF Bay ADU is a full-service Bay Area ADU contractor offering design, permitting, and construction for units from 600–1,200 sq ft. Options include studio, 2bed/2bath, garden cottage, and in-law suites for rental income or multigenerational livin... read more

Edri Construction, Inc. Mill Valley

1 Belvedere Pl, Mill Valley, CA 94941 27.7 miles

Eco-Friendly Luxury Builds

Edri Construction, Inc. is a Mill Valley-based Bay Area ADU contractor offering full-service accessory dwelling unit construction, including garage conversions, detached ADUs, JADUs, and in-law suites, with permit handling and energy-efficient bui... read more

Reno Revive Remodeling

2655 Stanwell Drive, Concord, CA 94520 33.1 miles

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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Gordon Reese

100 Pringle Avenue, Walnut Creek, CA 94596 28 miles

Licensed 41 years in business

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

Other cities in California

• North Highlands
• Sacramento
• North Hollywood
• Agoura Hills
• Encino
• Los Angeles
• Tarzana
• Long Beach
• Hollywood
• Glendale
• Valley Village
• Pasadena
• Burbank
• Downey
• Beverly Hills

What you need to know

ADU Contractors in San Mateo: Building in One of the Bay Area's Most Sought-After Cities

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 ADU Regulations and Permitting Requirements

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:

• Maximum ADU size: Detached ADUs can be up to 1,200 square feet, while attached ADUs are generally limited to 50% of the primary dwelling's square footage.
• Setback requirements: A minimum 4-foot rear and side setback is typically required for new detached ADUs.
• Height limits: Detached ADUs are generally limited to 16 feet in height, though this can vary by zone.
• Owner-occupancy rules: California state law has suspended owner-occupancy requirements for ADUs through 2025, giving San Mateo homeowners more flexibility.
• Parking: In many cases, ADUs in San Mateo do not require additional parking spaces, especially when located near transit corridors.

Why You Need a Local ADU Contractor in San Mateo

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.

Types of ADUs Popular in San Mateo

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:

1. Detached ADUs: Standalone structures in the backyard, ideal for larger lots.
2. Attached ADUs: Extensions of the existing home, sharing at least one wall.
3. Garage Conversions: Transforming an existing garage into a livable unit, a popular and cost-effective option.
4. Junior ADUs (JADUs): Units up to 500 square feet created within the existing home's footprint.

Choosing the Right ADU Contractor in San Mateo

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.