ADU Contractors in California
Kol & Co
23431 Blue Bird Dr, Lake Forest, CA 92630
Kol & Co. is an ADU contractor serving Orange County, West LA & North San Diego. With 15+ years in design-build, they handle detached ADUs, garage conversions, JADUs & more—managing permits, design, and construction under one roof.read more
Build ADU Home Remodel
4780 West Mission Boulevard, Montclair, CA 91762
Build ADU Home Remodel is a trusted, licensed general contractor serving homeowners throughout the Inland Empire with full-service ADU construction. Whether you're looking to add rental income, house extended family, or increase your property valu... 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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G&M Home Remodeling
4902 Coldwater Canyon Avenue, Sherman Oaks, CA 91423
G&M Home Remodeling is a trusted ADU contractor in Los Angeles offering detached ADUs, garage conversions, granny flats, and JADUs. Based in Sherman Oaks, they handle permitting, design, and construction across the greater LA area.
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Wise Builders
2355 Paragon Drive, San Jose, CA 95131
Wise Builders is a Bay Area ADU contractor with 20+ years of experience in accessory dwelling units, garage conversions, and attached or detached ADU construction across San Jose, Sunnyvale, and Silicon Valley. Free estimates available.
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H&M Building Services LLC
7413 El Cajon Boulevard, La Mesa, CA 91942
H&M Building Services LLC builds ADUs in San Diego using a 3-phase process: site feasibility, design/engineering, and full construction. Projects average 6–10 months, with Buildertrend portal updates and turnkey delivery upon final occupancy... read more
ADU Cities
1420 East Katella Avenue, Anaheim, CA 92867
ADU Cities is a California design-build firm specializing in ADUs, JADUs, garage conversions, and remodels. They manage design, permitting, and construction, helping homeowners add living space, boost property value, or generate rental income.
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Green Design and Build
16120 Sherman Way, Van Nuys, CA 91406
Licensed, veteran-owned ADU builder in Van Nuys. Detached, attached and junior ADUs plus garage conversions, with design, permits and construction handled under one roof.
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Step Up Builders Inc
16250 Ventura Boulevard, Encino, CA 91436
Step Up Builders Inc is a Class A licensed ADU contractor in Encino, CA, serving Los Angeles, San Fernando Valley & Inland Empire. 30+ years experience in detached ADUs, garage conversions, JADUs & remodels. Free estimates available.
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Leon's Construction Inc.
3333 Vaca Valley Parkway, Poway, CA 95688
Leon's Construction Inc. offers ADU construction services in Escondido, Encinitas, and San Marcos, CA. They build backyard cottages, basement apartments, tiny homes, and more using durable, energy-efficient materials.
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LA Developing Inc.
8504 Firestone Boulevard, Downey, CA 90241
An Accessory Dwelling Unit (ADU) adds value, rental income, and flexibility to your property. LA Developing Inc. specializes in ADU construction in Los Angeles, offering garage conversions, detached builds, and attached additions with full project... read more
9 Builders
San Jose, CA 95122
9 Builders is a Bay Area ADU contractor offering full-service design, permits & construction. Specializing in detached ADUs, garage conversions & additions, costs range $150K–$350K, taking 8–14 months to complete.
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Baystar - Garage Remodel
2074 Walsh Avenue, Santa Clara, CA 95050
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
RL Remodeling
4360 Twain Avenue, San Diego, CA 92120
RL Remodeling offers garage conversions, room additions, and ADU construction. With nearly 50 years of combined experience, they handle design, permits, and execution. Garage ADU conversions typically cost $30K–$60K+, offering strong rental inco... read more
Proteus Homes
793 North Avenue, Vista, CA 92083
Proteus Homes is a custom home and ADU builder with 30+ years of experience in the Southwest US. They offer full-service ADU construction, including design, permitting, and panelized off-site fabrication, with move-in-ready homes in under three mo... 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.