ADU Contractors in California
CCS Inc.
5535 Balboa Boulevard, Encino, CA 91316
CCS Inc. offers ADU construction, garage conversions, remodeling & permit services in Long Beach, CA. Costs range from $100K–$400K+, with timelines of 4–14 months. Free consultations available for eligible residential properties.
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Jackson & Sands Engineering
900 East Main Street, Grass Valley, CA 95945
Jackson & Sands Engineering offers ADU plan design & engineering services across California. Options include custom designs or prepackaged plans. Trusted in permit ready programs for cities like Chico, Truckee & Placer County.
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AKD Homes
3518 Arden Road, Hayward, CA 94545
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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Falcon Builders Group
8825 Aero Drive, San Diego, CA 92123
Falcon Builders Group is a San Diego ADU contractor specializing in detached ADUs, garage conversions, JADUs, in-law suites, and casitas. They guide homeowners through design, permitting, and construction to add functional, value-boosting living space.
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Safeway Construction
67 West Easy Street, Simi Valley, CA 93065
Convert your garage into a legal ADU in Ventura County. Costs range $53K–$103K, with rental income of $1,700–$2,600/month and a 4–5 year payback. Safeway Construction handles design, permits & build.
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Monterey Bay Design Group
13770 Center Street, Carmel Valley Village, CA 93924
Monterey Bay Design Group, based in Carmel Valley, CA, specializes in ADU design, permitting, and construction. They help homeowners build granny flats, garage conversions, and in-law suites to generate rental income and increase property value.
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Ohayon Construction
Los Angeles, CA 90012
Ohayon Construction is a licensed Los Angeles ADU contractor since 2008. They build detached ADUs, garage conversions, attached ADUs & JADUs. Serving Beverly Hills, Santa Monica & more. Free consultation available.
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Delerio Construction
3741 West Gettysburg Avenue, Fresno, CA 93722
Delerio Construction, serving Fresno since 2006, specializes in ADU building and home remodeling. They offer flexible ADU designs for extra living space, home offices, or rentals, plus kitchen, bathroom, flooring, and window services.
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Premium ADU
5161 Lankershim Boulevard, North Hollywood, CA 91601
Premium ADU is a Los Angeles ADU specialist offering design, permitting, and construction of detached ADUs, garage conversions, and JADUs. Operating since 2021 with an in-house team, projects typically complete in 6–12 months.
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Humbuildt Homes
1250 Giuntoli Ln, Arcata, CA 95521
Humbuildt Homes is an Arcata, CA general contractor specializing in sustainable prefabricated homes for Humboldt County. They offer affordable, energy-efficient housing guided by integrity, innovation, and quality, with a streamlined build process from consultation to completion.
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ADU by Kn Remodeling
19709 Ventura Boulevard, Woodland Hills, CA 91364
KN Remodeling is a certified ADU contractor serving Los Angeles, Woodland Hills, Simi Valley & Thousand Oaks. Specializing in detached ADUs, attached ADUs & garage conversions, they handle design, permits & construction with 100+ ADU plans completed.
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Sten Engineering
601 South Brand Boulevard, San Fernando, CA 91340
Sten Engineering is a Los Angeles firm specializing in ADU design, structural engineering, and garage conversions. Led by licensed P.E. Evgeny Nagovitsyn, they handle permits, structural plans, and ADU builds across Southern California.
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Second Dwellings
100 Higgins Canyon Road, Half Moon Bay, CA 94019
ADU Builders Group
15166 Los Gatos Boulevard, Los Gatos, CA 95032
ADU Builders Group is a Bay Area family-owned ADU contractor with 21+ years of experience. They build attached, detached, converted, and junior ADUs, offering full design-build services, permitting support, a 3-year warranty, and a 10-year structural guarantee.
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California Tiny House
3630 North Hazel Avenue, Fresno, CA 93722
California Tiny House, based in Fresno, CA, builds custom tiny homes, ADUs, granny flats & commercial structures. Offering in-stock models, DIY programs & financing via 21st Mortgage for residential & commercial clients.
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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.