ADU Contractors in California
Stephens Brothers Construction
31779 Fallbrook Circle, Murrieta, CA 92563
Stephens Brothers Construction is Temecula & Murrieta's top ADU builder since 2011, offering detached ADUs, JADUs, garage conversions & casitas. Costs from $300–$350/sq ft. Licensed, hands-on, and serving all of Riverside County.
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Bergstrom Construction Inc.
10232 I Avenue, Hesperia, CA 92345
Bergstrom Construction Inc. builds custom ADUs in Apple Valley, Victorville & Hesperia. Serving San Bernardino County, they offer in-law suites, backyard cottages, home offices & garage additions tailored to High Desert homeowners.
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QUH Studio
120 East Tehachapi Boulevard, Tehachapi, CA 93561
QUH Studio, based in Tehachapi, CA, offers ADU design, architectural drafting, and construction documents for California homeowners. Services include floor plans, 3D renderings, permit support, and interior architecture for residential and commerc... read more
AD Remodeling & Construction
7040 Darnoch Way, West Hills, CA 91307
AD Remodeling & Construction offers room additions and ADU services, including design, permitting, and construction. They build detached ADUs, in-law suites, granny flats, and room additions tailored to client needs and local regulations.
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JS Moody Construction
PO Box 13745, San Luis Obispo, CA 93406
JS Moody Construction offers full-service ADU construction in San Luis Obispo, CA. Services include detached ADUs, garage conversions, in-law suites & backyard cottages. They handle design, permits & build management for hassle-free result... read more
Collins Remodeling
2651 Blanding Avenue, Alameda, CA 94501
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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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 structu... read more
Homes by Hedges
PO Box 2586, Valley Center, CA 92082
Homes by Hedges is an experienced ADU contractor in North San Diego County, building granny flats, casitas & garage conversions. Serving Valley Center, Escondido & more for 25+ years, managing permits & local zoning regulations.
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Tims New Construction
931 Broxton Avenue, Los Angeles, CA 90024
Tims New Construction is a Los Angeles contractor specializing in ADU, Junior ADU, and garage conversions. Services include custom design, permitting, and full builds. They also support SB9 projects, helping homeowners add rental units or family h... read more
L Square Construction
Irvine, CA 92705
L Square Construction is an ADU contractor serving Los Angeles & Orange County, CA. They offer full-service design-build ADU solutions including detached units, in-law suites, garage conversions, and energy-efficient builds with solar integrat... read more
Sideline Builders Inc
4676 Hessel Road, Sebastopol, CA 95472
If you’re considering adding an accessory dwelling unit to your home, contact your local ADU contractors near Sebastopol: Sightline Builders. Locally owned and operated in Sonoma County, they have over 28 years of experience in the construction ... read more
Y9 Construction
10637 Roselle Street, San Diego, CA 92121
Humboldt ADU
3015 H Street, Eureka, CA 95501
Humboldt ADU is a Humboldt County program helping homeowners build Accessory Dwelling Units (ADUs) like granny flats or backyard cottages to boost affordable housing. It offers guides on types, permits, financing, and construction.
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Oasis Builders
11500 West Olympic Boulevard, Los Angeles, CA 90064
Oasis Builders is a trusted ADU contractor serving Greater Los Angeles, specializing in detached ADUs, attached ADUs, and garage conversions. Costs range from $100K–$300K, with timelines of 6–12 months. Full-service: permits, blueprints & ... read more
Markis Construction
14126 Sherman Way, Van Nuys, CA 91405
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.