ADU Contractors near San Mateo, CA
Santa Cruz Construction Experts
303 Potrero Street, Santa Cruz, CA 95060
42.3 miles
Santa Cruz Construction Experts builds ADUs in Scotts Valley, CA, including detached units, granny flats & in-law suites. They also construct pool houses, garages & outdoor spaces, ensuring local code compliance.
read more
C.J. Skeeles General Contractor
24845 Canyon View Court, Hayward, CA 94541
15.8 miles
C.J. Skeeles General Contractor specializes in ADU construction in Hayward, Oakland & San Francisco, CA. Services include detached ADUs, garage conversions & interior conversions, all built to California zoning & permitting requirement... read more
Bay Villa Builders
36007 Bayonne Drive, Newark, CA 94560
14.7 miles
Bay Villa Builders brings over 50 years of combined experience in crafting expertly designed ADUs that enhance both your home's functionality and its value. An Accessory Dwelling Unit, or ADU, serves as an additional living space on your property.... read more
Baystar - Garage Remodel
2074 Walsh Avenue, Santa Clara, CA 95050
23.1 miles
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
ADU Home Addition
68 Centre Street, Mountain View, CA 94041
16.9 miles
ADU Home Addition is a leading Bay Area ADU contractor with 12+ years of experience. They specialize in custom ADU construction, in-law suites, garage conversions, home additions, and rental-optimized ADUs, handling design, permits, and full const... read more
Edri Construction, Inc. Berkeley
2120 University Ave, Berkeley, CA 94704
22.2 miles
Edri Construction, Inc. is a Berkeley-based general contractor specializing in ADU construction across the Bay Area. Services include garage conversions, detached ADUs, attached additions, granny flats, and custom interiors, with full project mana... read more
Elite ADU Santa Cruz
347 Soquel Avenue, Santa Cruz, CA 95062
42.9 miles
Elite Construction builds ADUs in Santa Cruz County, offering detached units, garage conversions & addition ADUs. Projects range 250–1,200 sq ft, cost $115K–$450K, and take 6–9 months. Free estimates available.
read more
DeBrus Construction LLC
820 Arguello Boulevard, San Francisco, CA 94118
17.3 miles
DeBrus Construction LLC is a San Francisco general contractor specializing in seismic retrofits, foundation repair, ADU construction, and home remodeling. Led by Malcolm DeBrus, the company handles mandatory soft story retrofits, garage conversion... read more
Epic Modulars
157 North 4th Street, San Jose, CA 95112
27.4 miles
Epic Modulars delivers fast, flexible, and customizable solutions for homes and ADUs. Their manufactured homes and ADUs are built in controlled factory environments, ensuring superior quality, faster timelines, and predictable costs.
read more
Geico Builders
1901 Harrison Street, Oakland, CA 94612
17.8 miles
Geico Builders offers ADU services including detached ADUs, attached ADUs, Junior ADUs, garage conversions, and home additions. Ideal for rental income, family housing, or maximizing space on your existing property.
read more
DeHaro Construction Inc
6411 Brisa Street, Livermore, CA 94550
31.6 miles
Deharo Construction is a trusted ADU builder serving Livermore, Pleasanton, and Dublin. Specializing in accessory dwelling units, new construction, and home additions, they deliver custom granny flats, detached ADUs, and in-law suites across the T... read more
Soliz General Construction & Painting Inc
10069 Bernhardt Drive, Oakland, CA 94603
14 miles
Soliz General Construction & Painting Inc is a Bay Area ADU contractor with 20+ years of experience. They offer full-service ADU design and construction, including permits, structural work, and finishing for granny flats, in-law suites, and ba... read more
Edri Construction, Inc. Walnut Creek
1990 N California Blvd Ste 20, Walnut Creek, CA 94596
28 miles
Edri Construction, Inc. is a Walnut Creek-based ADU contractor serving the Bay Area. They specialize in garage conversions, detached ADUs, attached additions, in-law suites, and JADUs, handling design, permitting, and project management.
read more
Adapt Dwellings
5944 Claremont Avenue, Oakland, CA 94618
20.6 miles
ADUs add rental income & property value. Services include garage conversions, detached ADUs, JADUs & granny flats. ADU Feasibility Studies cover code, utilities & ROI. Architectural services via Adapt Dwellings ensure smooth approval t... read more
Feldman Construction
3392 Georgetown Place, Santa Clara, CA 95051
22 miles
Feldman Construction specializes in custom ADU design and construction across the Bay Area, including San Mateo and Santa Clara County. They build detached ADUs, granny flats, and in-law suites to boost property value and expand living space.
read more
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.