ADU Contractors in California
Delcoi
21650 Oxnard Street, Woodland Hills, CA 91367
Delcoi is an ADU contractor specializing in granny flats, casitas, in-law suites, detached ADUs, garage conversions, and backyard cottages. They handle permits, regulatory compliance, and quality construction to maximize living space and rental in... read more
Cousin Gary Homes - Chico
13468 California 99, Chico, CA 95973
Cousin Gary Homes, serving Chico since 1972, offers a wide range of ADU models—from 439 to 1,177 sq ft—including granny flats and backyard cottages. Visit their showroom at 13468 Highway 99 North to explore options.
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ADU Premium - Eco Tiny Houses
3421 Hollis Street, Oakland, CA 94608
ADU Premium builds eco-friendly, RVIA-certified tiny homes and ADA-accessible ADUs. Models range from 90–360 sq ft, starting at $49,200. Includes permits, delivery, and installation. Financing available via RV loans, HELOC, and more.
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Smart ADU Builder
6 Venture, Irvine, CA 92618
Smart ADU Builder offers customizable ADU floor plans from 400–1,200 sq ft, including granny flats, in-law suites & backyard cottages. Choose from 20+ pre-approved plans or custom designs with smart home features & energy-efficient syste... read more
The Los Angeles ADU Builders
240 South Beverly Drive, Beverly Hills, CA 90212
Los Angeles ADU Builders is a licensed ADU contractor in Beverly Hills offering custom ADU design, garage conversions, detached ADUs, JADUs & in-law suites. CSLB certified, fully insured, with expert permit handling & transparent pricing.<... read more
Harmony Design & Development
5880 3rd Street, San Francisco, CA 94124
Harmony Design & Development builds custom ADUs across the San Francisco Bay Area, including detached units, garage conversions, and in-law suites. They manage permits, design, and construction from start to finish.
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Roof and Realm
2245 Vía De Mercados, Concord, CA 94520
Roof and Realm is a California-based steel-framed modular home and ADU builder offering fire, earthquake, and wind-resistant structures. Their eco-friendly builds use 98% recyclable materials, generate minimal waste, and support solar-ready, Net P... read more
JL Building Group
9424 Chesapeake Drive, San Diego, CA 92123
JL Building Group builds ADUs, granny flats, and garage conversions across San Diego County, including Carlsbad, Escondido & Chula Vista. They handle permits, design, and construction for rental units or family living spaces.
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Aspace Studios
p.o. box 851, Glendora, CA 91741
Aspace Studios is an LA-based design-build firm specializing in ADUs and residential expansions. They handle detached, attached, garage conversion, and JADU projects, guiding homeowners through design, permitting, and construction.
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YOR Construction
12135 Miranda Street, Valley Village, CA 91607
An ADU (accessory dwelling unit) is a secondary home on a residential lot. Garage conversion ADUs are cost-effective options. YOR Construction, an LA-based ADU contractor, specializes in garage conversions tailored to homeowner needs.
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HardyBuilt Custom Construction Inc.
1151 Hayes Road, McKinleyville, CA 95519
HardyBuilt Custom Construction Inc. is a licensed General Contractor in Humboldt County, CA, specializing in custom homes, ADU builds, whole house remodels, additions, and kitchen & bathroom renovations built for Marine Climate Zone 4C.
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ADU Crew
6680 Alhambra Avenue, Martinez, CA 94553
Your Prefab ADU will be delivered and installed to your site. All ready to enjoy a sustainable home to last for generations.
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MTZ Contractors
3515 Atlantic Avenue, Long Beach, CA 90807
Looking for the best ADU construction? Choose Mtz Contractors Inc to completely transform your property, known for constructing excellent ADUs in Long Beach CA. We create and build Accessory Dwelling Units that meet your precise requirements for q... read more
Hive ADU
635 State St, Ste 212, Santa Barbara, CA 93101
Hive ADU is a Santa Barbara ADU builder that helps homeowners plan, design, permit, and build custom detached ADUs through a feasibility-first design-build process. Our team focuses on site review, permitting strategy, design coordination, and con... read more
ASL Remodeling
690 Saratoga Avenue, San Jose, CA 95129
ASL Remodeling is a California licensed ADU contractor (CSLB #1060310) with 20+ years experience and 300+ completed projects. Services include detached ADUs, garage conversions, granny flats, JADUs, and in-law suites with full design-build support... read more
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.