ADU Contractors in California
New Era Home Services
Long Beach, CA 90815
New Era Home Services LLC is a full-service ADU builder specializing in custom accessory dwelling units, including granny flats, rental units, and garage conversions, guiding homeowners through design, permitting, and construction.
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Joy Line Homes
3110 Mission Drive, Capitola, CA 95065
Joy Line Homes offers the ADURA ADU Series — factory-built backyard cottages and granny flats featuring modern design, high-end finishes, and durable materials. An affordable, plan-based ADU solution for homeowners seeking quality detached accessory dwelling units.
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Zieba Builders
1390 East Burnett Street, Signal Hill, CA 90755
Zieba Builders, a Southern California design-build firm, was named one of the top 7 ADU contractors in Long Beach by Home Builder Digest. They specialize in custom homes, garage conversions, granny flats & detached ADUs.
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ExpandADU | Prefab ADUs
41111 Mission Boulevard, Fremont, CA 94539
ExpandADU is a California-based prefab ADU builder offering full-service accessory dwelling unit construction, including consultation, design, planning, and build. Serving the Bay Area and beyond, they specialize in detached ADUs, granny flats, and JADUs.
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Aurea Construction
516 Pennsfield Place, Thousand Oaks, CA 91360
Aurea Construction, based in Thousand Oaks, CA, specializes in ADUs, garage conversions, room additions, sunrooms & second story additions. They manage full projects from design to permits, serving local homeowners seeking quality home expansion solutions.
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Perpetual Homes ADU
4115 Blackhawk Plaza Circle, Danville, CA 94506
Perpetual Homes is a Northern California ADU builder with 40+ years of experience. They offer customizable prefab ADUs, a 10-step process, no site work markup, Energy Star insulation, a 7-year warranty, and an A+ BBB rating.
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ADU Builders Placer
1390 Lead Hill Blvd, Roseville, CA 95661
ADU Builders Placer is a trusted ADU contractor in Roseville, CA, specializing in custom accessory dwelling unit design, construction, permitting, and financing. They offer sustainable, affordable ADU solutions including granny flats, in-law suites, and backyard cottages.
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ADU Designers & Builders
2461 East Orangethorpe Avenue, Fullerton, CA 92831
ADU Designers & Builders is a full-service ADU contractor in Fullerton, CA, offering detached ADUs, garage conversions, attached ADUs & JADUs across Southern California, with expert design, permitting, solar integration & 0% financing options.
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Smith and Son Construction
1771 Vineyard Drive, Antioch, CA 94509
At Smith and Son Construction, they specialize in designing and building high-quality ADUs in San Leandro, CA. Whether you envision a private guest house, a rental unit, or a home office, they deliver innovative designs, expert craftsmanship, and a stress-free construction experience.
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Suncoast Construction Inc.
428 Sleeping Indian Road, Vista, CA 92057
Suncoast Construction Inc. is a licensed ADU contractor in Oceanside, CA, building detached ADUs, garage conversions, JADUs & attached units per Oceanside's 2022 ADU Ordinance. No short-term rentals permitted.
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IL Total Design
9655 Granite Ridge Drive, San Diego, CA 92123
IL Total Design & Build is a San Diego ADU specialist offering full-service design, permitting, and construction for granny flats, garage conversions, detached ADUs, and JADUs. They also provide home additions and remodeling across San Diego County.
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UADU
1702 S. Robertson Blvd. #177, Los Angeles, CA 90035
UADU is a California ADU contractor offering garage conversions, detached, attached, and two-story ADUs. They handle design, permits, and construction. Free feasibility checks available. Projects typically take 4–6 months.
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ADU Los Angeles
3744 Flower St, Los Angeles, CA 90007
ADU Los Angeles (ADLA) is a specialized ADU contractor serving LA County. They offer consulting, custom design, construction, garage conversions, basement ADUs, attached and detached units, helping homeowners maximize property value.
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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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Mountain Top Construction
30 North San Pedro Road, San Rafael, CA 94903
Mountain Top Construction is a Bay Area ADU builder serving San Rafael, San Francisco, and Las Vegas. They specialize in detached ADUs, backyard cottages, granny flats, and in-law suites, managing design, permitting, and construction.
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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.