View ADU Builders is a trusted Los Angeles ADU contractor specializing in detached ADUs, garage conversions, attached ADUs & in-law suites. Costs range from $80K–$350K+. Free 3D design consultations available.
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Valley Home Builders Inc. is a Silicon Valley design-build contractor serving Santa Clara & San Mateo Counties. Founded in 2005, they specialize in kitchen remodeling, ADU construction, and home renovations across San Jose, San Mateo & beyond.
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Avorino specializes in ADU construction, offering detached, attached, garage conversion, and above-garage units. Projects range from $250K–$400K, covering design, permitting, and build phases over 10–14 months.
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Murray Lampert, San Diego's trusted ADU builder since 1975, offers full design-build services including granny flats, in-law suites, and garage conversions. With 50+ years of experience, they deliver custom, high-quality accessory dwelling units tailored to your needs.
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DSA Architects designed an 850 sq. ft. second-floor ADU in Berkeley Hills for multi-generational living. Features 2 beds, 1 bath, open layout, Tilden Park views, roof deck, solar PV, heat pumps, and gray-water system.
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Ataman Studio is a trusted ADU contractor in Los Angeles, serving all of California. Full-service design, permitting, and construction for detached ADUs, garage conversions, and in-law units, with compliance to local zoning and state regulations.
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Barcci Builders specializes in ADU construction across the Bay Area, offering design, permitting, and build services. With 40+ completed units, they handle JADUs, garage conversions, attached, and detached ADUs, with costs ranging from $60K to $400K+.
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Building an ADU in Riverside takes 8–16 months. JDB Builders guides homeowners through design (1–3 months), permitting (2–4 months), construction (4–8 months), and final inspections (1–2 months) for granny flats, garage conversions, and more.
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JP Homes is a licensed ADU contractor in Southern California, serving Los Angeles, Orange County, Riverside & San Bernardino. They offer full-service ADU construction including detached units, garage conversions & more.
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Type Five is a Berkeley, CA-based ADU builder offering custom backyard cottages, granny flats & in-law suites. They combine modular design, transparent pricing & streamlined construction for stress-free, high-quality detached ADUs built to last.
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ADU Custom Homes is a licensed California ADU contractor with 35+ years of experience serving LA, Orange & Riverside counties. They specialize in detached ADUs, garage conversions & additions, managing projects from permits to Certificate of Occupancy.
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West Coast ADU is a California-based ADU builder offering prefab & manufactured accessory dwelling units. They help homeowners add rental income, house family members & boost property value with streamlined permitting & construction.
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Gordon Reese Design Build is a licensed ADU contractor in Walnut Creek, CA, with 41+ years of experience. They offer custom ADU design and construction, 3D renderings, transparent pricing, serving the Bay Area including Danville, Lafayette & Concord.
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prefabADU is a Bay Area ADU builder with 16+ years of experience offering affordable kits and plans from under $45K. With 12 state-approved plans valid across California, they simplify permits, design, and installation for homeowners.
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Mendez and Son's Construction is a Bay Area ADU contractor offering design-build services in Palo Alto, Mountain View, San Mateo & Walnut Creek. They handle detached ADUs, garage conversions & JADUs, managing permits to final inspection.
read moreCalifornia 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.
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.
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:
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.
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.