ADU Contractors in California
Clever Design & Remodeling
1630 Oakland Road, San Jose, CA 95131
Clever Design & Remodeling builds ADUs across the San Francisco Bay Area, including garage conversions, attached, detached, and junior ADUs. Services cover permits, construction, interior design, and landscaping. Average ADU cost is ~$145,000.
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Modern Granny Flat San Diego
5727 Adelaide Avenue, San Diego, CA 92115
ModernGrannyFlat is San Diego's ADU & granny flat specialist, offering eco-friendly, affordable accessory dwelling units. Services include garage conversions, detached ADUs, & JADUs, guiding homeowners through design, permits & construction under California ADU laws.
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Joel & Co. Construction
11693 San Vicente Boulevard, Los Angeles, CA 90049
Joel & Co. Construction, serving Los Angeles since 1983, offers expert residential & commercial construction, including custom homes, kitchen & bathroom remodels, ADUs, room additions, and general contracting across Beverly Hills, Santa Monica & beyond.
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Pro-built Homes
112 King Street, New Brunswick, CA E1N 2N6
Pro-built Homes builds factory-constructed Accessory Dwelling Units (ADUs) delivered 99% complete. Ideal as in-law suites, rental units, or backyard cottages, their ADUs offer quality, speed, and long-term value with minimal on-site disruption.
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Santa Barbara ADU Solutions
121 South Hope Avenue, Santa Barbara, CA 93105
ADU Services is a premier ADU contractor in Santa Barbara, CA, specializing in custom accessory dwelling units including granny flats, backyard cottages, and in-law suites. They offer full project management, flexible customization, and sustainable, energy-efficient construction.
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MyADU4Less
579 West County Line Road, Calimesa, CA 92320
MyADU4Less is a Southern California ADU builder specializing in prefabricated accessory dwelling units. Offering models from 160–1,200 sq ft, they handle design, permitting, and construction. CalHFA grants up to $40,000 may apply.
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Molinar Design
1132 Spence Street, Los Angeles, CA 90023
Molinar Design is a licensed design-build firm in Los Angeles offering ADUs, garage conversions, custom homes, remodeling, commercial architecture, permit packages, and fire & water damage restoration across Los Angeles County.
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Summit Building Group
1401 21st Street, Sacramento, CA 95811
Sacramento's Summit Building Group offers full-service ADU construction, including custom design, permitting, garage conversions, and detached units. They serve homeowners seeking rental income, multigenerational living, or guest suites, backed by a lifetime workmanship warranty.
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Cousin Gary Homes - Sacramento
4920 Westside Road, Sacramento, CA 96001
Cousin Gary Homes – Sacramento specializes in ADU & JADU construction, offering 80+ floor plans from 546–2,536 sq. ft. Benefits include added property value, rental income & flexible living. California's 2023 ADU laws make building easier than ever.
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Horizon Remodeling Inc.
614 South Euclid Street, Fullerton, CA 92832
Horizon Remodeling Inc. is a full-service residential remodeling company offering kitchen, bathroom, roofing, flooring, painting, and ADU conversions. Dedicated project managers coordinate all trades, keeping projects on schedule and within budget.
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LA ADU Solutions Inc.
Los Angeles, CA 90012
Accessory Dwelling Units (ADUs) offer California property owners passive income, elderly care solutions, and property value growth. Since 2020 legislation, ADU permits are easier to obtain. Construction costs range $350–$450/sq ft, with rental income potential up to $4,000/month.
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Mills Builders Inc
2012 H Street, Sacramento, CA 95811
Mills Builders Inc is a Sacramento-based residential construction firm founded in 1999. Specializing in ADU construction, home renovation, in-fill development, and whole-house builds, they serve Sacramento's historic neighborhoods with decades of hands-on expertise.
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Built Environment Inc
365 Crother Road, Meadow Vista, CA 95722
Built Environment Inc. is a licensed Northern California ADU contractor with 20+ years of experience. They build detached, attached, internal, JADU, and garage conversion ADUs, guiding homeowners from consultation to completion per California building codes.
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Bartona Builders
331 Delaware Road, Burbank, CA 91504
Bartona Builders specializes in ADU construction in Los Angeles, offering detached ADUs, garage conversions, and in-law suites. They manage the full build process, ensuring code-compliant construction that adds value to residential properties.
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USModular Inc.
579 West County Line Road, Calimesa, CA 92320
USModular Inc. is a Temecula, CA ADU builder specializing in modular, prefabricated construction. Units are up to 90% factory-built, completed in ~120 days, and comply with IRC and local codes. Services include feasibility studies, design, engineering, permitting, and installation.
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Other cities in California
What you need to know
ADU Contractors in California: Navigating the Golden State's Unique Landscape
California is at the forefront of the Accessory Dwelling Unit (ADU) movement in the United States. With one of the most severe housing shortages in the nation, the state has enacted sweeping legislation to make ADU construction more accessible. Since 2020, California laws such as AB 68, AB 881, and SB 13 have significantly reduced barriers, eliminating minimum lot size requirements, reducing setback rules, and streamlining the permitting process. For homeowners looking to add value to their property or create additional rental income, working with experienced ADU contractors in California has never been more important.
What California ADU Contractors Must Know About State Regulations
Professional ADU contractors operating in California must stay current with a constantly evolving regulatory environment. Under California law, local agencies are required to approve or deny ADU permit applications within 60 days. Additionally, ADUs under 800 square feet cannot be denied solely based on floor area ratio limits. Contractors must also be familiar with owner-occupancy rules, utility connection requirements, and fire safety standards that vary by county and municipality. Cities like Los Angeles, San Diego, and San Jose each have their own local ordinances layered on top of state law, making local expertise a critical asset.
Types of ADUs Built by California Contractors
Experienced California ADU contractors are skilled in building a wide variety of ADU types to suit different property configurations and homeowner needs. The most common types include:
- Detached ADUs: Standalone structures built in the backyard or side yard of a primary residence.
- Attached ADUs: Units that share a wall with the main home, often built as additions.
- Garage Conversions: Transforming existing garages into livable spaces, a popular and cost-effective option.
- Junior ADUs (JADUs): Units up to 500 square feet created within the existing footprint of a home.
How to Choose the Right ADU Contractor in California
Selecting the right contractor is one of the most critical decisions in any ADU project. Homeowners should look for contractors who hold a valid California Contractors State License Board (CSLB) license, ideally a Class B General Building Contractor license. It is also important to verify that the contractor carries proper liability insurance and workers' compensation coverage. Look for professionals with a proven track record of successfully permitted ADU projects in your specific city or county.
The Benefits of Building an ADU in California
Building an ADU in California offers significant financial and lifestyle benefits. Homeowners can generate rental income to offset mortgage costs, house family members, or increase overall property value. In high-cost markets like the San Francisco Bay Area or Los Angeles, a well-built ADU can add hundreds of thousands of dollars in property value. With the right California ADU contractor by your side, the process can be smooth, compliant, and highly rewarding.