ADU Contractors in California
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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Los Angeles Advanced ADU Builders
240 South Beverly Drive, Los Angeles, CA 90212
Los Angeles Advanced ADU Builders offers full-service ADU construction across LA, including garage conversions, detached units, JADUs & prefab ADUs. With 20+ years experience & 500+ builds, they handle design, permits & zoning compliance.
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Halsell Builders
2325 Skyway Drive, Santa Maria, CA 93455
As a full-service construction company focused exclusively on ADUs and multifamily housing, we guide you through every step—from initial concept to final walkthrough. Whether you're adding a high-quality ADU to your property or developing affordable housing solutions for your community, we deliver spaces that are functional, personal, and built to last.
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Pixel Arch LLC
24001 Calle De La Magdalena, Laguna Hills, CA 92653
Pixel Arch LLC, Glendale CA, offers residential architecture services including custom home design, ADUs, garage conversions, duplexes & remodeling. Permit-ready plans, Title 24 reports & 3D renderings for California clients.
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Organic ADU
4432 Ingraham Street, San Diego, CA 92109
California ADUs (granny flats) add rental income or family housing to existing lots. Detached units up to 1,200 sq ft are allowed. Building costs start at $1,200/sq ft. Hire a specialized ADU contractor in San Diego for permits and zoning compliance.
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DB Construction
4555 Valley Boulevard, Los Angeles, CA 90032
DB Construction is a full-service ADU contractor in Greater Los Angeles, building detached ADUs, garage conversions, JADUs, in-law suites, and room additions. They manage permits in-house, offering transparent costs and turn-key project completion.
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Block Contracting
4268 Bonita Dr, Oceanside, CA 92056
Block Contracting specializes in crafting the best Accessory Dwelling Units (ADUs) in Oceanside, CA. Our designs are meant to enhance your property’s value and functionality. Whether you’re seeking a modern guest house, a stylish rental unit, pool house, or a versatile space for family.
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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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United Builders Development, Inc
25350 Magic Mountain Parkway, Santa Clarita, CA 91355
Building an ADU boosts property value, generates rental income, and offers flexible living space. United Builders, a licensed ADU contractor, delivers expert design-build solutions, garage conversions, and custom ADUs on time and within budget.
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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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GLAD Construction ADU Builders
3600 Madison Avenue, North Highlands, CA 95660
California offers ADU funding via CalHome, LEAP, LHTF, REAP, SB 2 grants & CDBG. Local programs in San Diego, San Jose & more aid homeowners. GLAD Construction ADU Builders guides projects from permits to completion.
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Bastion Structures
3111 Camino Del Rio North, San Diego, CA 92108
Bastion Structures offers modular concrete masonry homes, ADUs, and tiny houses that are fire-, mold-, and termite-resistant. Models range from 305 SF studios to 3,955 SF homes, ideal for California properties seeking durable, weatherproof living solutions.
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Fortune ADU
9810 Scripps Lake Drive, San Diego, CA 92131
Fortune ADU is a Southern California ADU contractor offering full-service design, permitting, and construction. Services start at $3,999.99, covering detached ADUs, JADUs, garage conversions, and more, with most projects completed in 6–12 months.
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J's Vision Construction
14340 Ventura Boulevard, Sherman Oaks, CA 91423
J's Vision Construction offers residential & commercial remodeling, including kitchen & bathroom remodels, ADU garage conversions, swimming pools, room additions, roofing, plumbing, flooring, and more — all managed under one general contractor.
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Forever Builders Inc
9619 Chesapeake Drive, San Diego, CA 92123
Forever Builders Inc is San Diego's premier ADU contractor, specializing in granny flats, in-law suites, and detached accessory dwelling units. They handle design, permitting, construction, and finishing, delivering high-quality, custom ADU solutions for homeowners.
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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.