ADU Builders California is a tech-driven ADU contractor offering detached ADUs, granny flats & garage conversions statewide. Costs range $30K–$300K+, with builds taking 4–6 months. Free consultations available.
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Larson Shores Architects is a San Francisco-based firm offering residential, ADU, and commercial design services. Founded in 2007 by Josh Larson, they specialize in new builds, garage conversions, in-law suites, and full permit navigation across the Bay Area.
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Framework First is a family-owned ADU builder in Monterey County, CA, with 40+ years of experience. They offer modular ADUs from 450–1,200 sq ft, handling permits, delivery, and installation with transparent pricing.
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A1 Building Contractors LLC offers general contracting, renovation, and ADU construction services. Specializing in detached ADUs, garage conversions, JADUs, and in-law suites, they manage permits, trades, and timelines for residential and commercial projects.
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Elite Construction builds ADUs in Santa Cruz County, offering detached units, garage conversions & addition ADUs. Projects range 250–1,200 sq ft, cost $115K–$450K, and take 6–9 months. Free estimates available.
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Inspired ADUs is an architect-led ADU design firm serving the Bay Area and Southern California. With 20+ years of experience and 250+ ADUs permitted, they offer custom, panelized, and modular ADU solutions, plus interior design and SB9 lot split services.
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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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SFBay ADU is a Bay Area ADU contractor offering full-service design, permitting, and construction. Specializing in 600–1,200 sq ft units, they offer studio, 2-bed, garden cottage, and in-law suite options, with projects completed in as little as 6 months.
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Your Prefab ADU will be delivered and installed to your site. All ready to enjoy a sustainable home to last for generations.
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Cupertino ADU is Silicon Valley's premier ADU builder, specializing in accessory dwelling units for rental income, intergenerational living, home offices, and eco-friendly housing solutions tailored to Cupertino homeowners.
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Founded in 1986 by Mike Morain, KGM Construction is an A+ BBB-rated contractor offering residential remodeling, new home construction, ADUs, granny flats, garage conversions, commercial builds, and storm damage restoration with 35+ years of experience.
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Crest Backyard Homes is San Diego's trusted ADU builder, specializing in prefab, detached ADUs, granny flats & garage conversions. Their all-inclusive team guides homeowners from design to completion, ensuring code-compliant, high-quality accessory dwelling units.
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Pasadena Master ADU Builder is a top ADU contractor in San Gabriel Valley, offering detached ADUs, garage conversions, and JADUs. With 20+ years experience, 150+ projects, and 98% satisfaction, they deliver compliant, high-quality builds boosting property value by 20–30%.
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Ingenious General Construction is a BBB-certified, licensed contractor in Walnut Creek, CA, serving the East Bay. With 20 years of experience, they offer ADUs, kitchen & bathroom remodeling, home additions, pool construction, and landscaping.
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.