ADU Contractors near San Mateo, CA
OT Bay Builders
1580 Oakland Road, San Jose, CA 95131
25.8 miles
OT Bay Builders is a complete remodeling company with over 40 years of combined experience amongst our team. We’re expert Bay Area ADU builders in San Jose with a customer-first mindset. As a full-service ADU builder, you can trust us to remain ... read more
Home Quality Remodeling
1070 Concord Avenue, Concord, CA 94520
32.5 miles
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
Tiny Home Cottages
32155 South Tracy Boulevard, Tracy, CA 95377
49 miles
Tiny Home Cottages offers 30+ floor plans across RV Park Model Tiny Homes and Cottage Series HUD manufactured homes in Tracy, CA, serving California and Oregon. Options include ADU-specific AU Series layouts, display locations, and financing for b... read more
ExpandADU | Prefab ADUs
41111 Mission Boulevard, Fremont, CA 94539
20.7 miles
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
S.D White Construction Inc
1151 Hensley Street, Richmond, CA 94801
27.4 miles
S.D White Construction Inc, a licensed Bay Area ADU contractor with 20+ years experience, builds detached, attached, garage conversion & above-garage ADUs in Richmond, CA. Full-service from design & permits to final inspection, completed i... read more
Collins Remodeling
2651 Blanding Avenue, Alameda, CA 94501
15.6 miles
Collins Remodeling is a licensed ADU contractor in Alameda, CA, specializing in detached ADUs, garage conversions, JADUs, and granny flats. They manage permitting, design, and construction, helping homeowners add value and rental income.
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California Building and Remodeling
1900 Camden Avenue, Albany, CA 95124
29.3 miles
California Building and Remodeling offers ADU construction, kitchen & bathroom remodeling, roofing, and concrete services in Albany, CA and the Bay Area. Experienced ADU contractor serving Albany, Berkeley, Richmond & more.
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Atlas Construction
101 Jefferson Drive, Menlo Park, CA 94025
8.9 miles
Atlas General Construction delivers complete ADU construction for detached, attached, and converted structures. Our team manages every phase of development including zoning research, architectural coordination, structural engineering, Title 24 com... read more
King David Construction
3000 El Camino Real, Palo Alto, CA 94306
13 miles
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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AK Builders Inc
385 Woodview Avenue, Portland, OR 95037
45.3 miles
AK Builders Inc is a White Salmon, WA contractor serving the Columbia River Gorge. They offer new home builds, remodels, ADU projects, and custom woodworking across Oregon and Washington.
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Home Quality Remodeling
3033 Moorpark Avenue, San Jose, CA 95128
25.8 miles
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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GR Innovative Builders Inc.
12488 San Pablo Avenue, Richmond, CA 94805
26.8 miles
GR Innovative Builders Inc. is a Bay Area ADU contractor specializing in accessory dwelling units, granny flats, and in-law suites. Completed projects in Richmond, Oakland, Lafayette & Pinole. Featured in Sunset Magazine.
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AKD Homes
3518 Arden Road, Hayward, CA 94545
12 miles
AKD Homes is a SF Bay Area ADU contractor with 20+ years of experience. They offer full-service ADU design, permits, and construction, including detached ADUs, granny flats, and custom builds ranging from 400–750 sq. ft.
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ADU Builders Bay Area
111 N Market St Suite 1150, San Jose, CA 95113
26 miles
ADU Builders Bay Area specializes in detached ADUs, garage conversions, in-law suites & more. Expert ADU contractors offering transparent pricing, full permitting & quality construction throughout the Bay Area.
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Manzanita Design Build
408 48th Street, Oakland, CA 94609
19.7 miles
Manzanita Design Build is an East Bay ADU contractor specializing in accessory dwelling units. Serving Berkeley, Oakland, Alameda & more. New ADU construction starts ~$300K, 5–8 month build time. Licensed (#1034108) & insured.
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Other cities in California
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:
- Detached ADUs: Standalone structures in the backyard, ideal for larger lots.
- Attached ADUs: Extensions of the existing home, sharing at least one wall.
- Garage Conversions: Transforming an existing garage into a livable unit, a popular and cost-effective option.
- 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.