Basement Conversion in California
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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ADU 4 You Pros
Fresno, CA 93710
ADU 4 You Pros is a California Central Valley ADU contractor offering full-service accessory dwelling unit solutions, including detached ADUs, garage conversions, and in-law suites, handling design, permitting, and construction.
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Dream Build Services
3654 Thornton Ave, Fremont, CA 94536
Dream Build Services is a full-service ADU contractor in Fremont, CA, offering detached ADUs, garage conversions, basement conversions, and JADUs. Services include design, permits, electrical, plumbing, HVAC, and solar integration across the East Bay.
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House To Home
374 Encinitas Boulevard, Encinitas, CA 92024
House to Home is a trusted ADU builder in San Diego with 25+ years of experience. They specialize in granny flats, guest houses, garage conversions, and Junior ADUs, serving San Diego, Carlsbad, La Jolla & more.
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A+ Construction & Remodeling ADU Builders
3612 Madison Ave #33, North Highlands, CA CA 95660
A+ Construction & Remodeling is a top-rated ADU contractor in Greater Sacramento with 30+ years experience. They offer custom ADUs, garage conversions, granny flats & more, managing all permits and zoning compliance. CSLB Licensed #1007869.
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Streamline Design Group
500 La Terraza Boulevard, Escondido, CA 92025
Streamline Design Group offers ADU design and permitting in San Diego, covering detached, attached, JADU, garage conversions, and multi-family units. Referenced in the State ADU handbook, they deliver permit-ready plans at 40–60% less than architect fees.
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Alon Design & Remodeling
722 Charcot Avenue, San Jose, CA 95131
Alon Design & Remodeling is a leading ADU contractor offering detached, attached, garage conversion, basement, and JADU options. ADUs boost property value, generate rental income, and provide independent living spaces with full amenities.
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Musick Construction Inc.
1818 Peacock Boulevard, Oceanside, CA 92056
Musick Construction Inc. offers ADU construction services including new builds and conversions like garage and basement conversions. They handle permits, design, and finishes for granny flats, in-law suites, and rental units.
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King Home Remodeling
1012 West Beverly Boulevard, Montebello, CA 90640
King Home Remodeling builds detached, attached, garage conversion, basement, and junior ADUs in Montebello. Services include design, permitting, construction, and inspections. Local zoning, size limits, and parking rules apply.
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Modern Granny Flat San Diego
5727 Adelaide Avenue, San Diego, CA 92115
ModernGrannyFlat is San Diego's ADU & granny flat specialist, offering eco-friendly, affordable accessory dwelling units. Services include garage conversions, detached ADUs, & JADUs, guiding homeowners through design, permits & construction under California ADU laws.
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Edrington and Associates
5944 Claremont Avenue, Oakland, CA 94618
Edrington and Associates helps property owners add ADUs—garage conversions, detached units, or Junior ADUs. They offer ADU Feasibility Studies in three packages and a free 15-minute consultation to explore options.
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Cali Bath & Kitchen
5519 clairmont mesa blvd, San Diego, CA 92117
Cali Bath & Kitchen offers full-service basement conversions in San Diego. From design to finishing, their in-house crew handles plumbing, electrical, waterproofing & more. Projects take 6–10 weeks. Free consultations available.
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Delcoi
21650 Oxnard Street, Woodland Hills, CA 91367
Delcoi is an ADU contractor specializing in granny flats, casitas, in-law suites, detached ADUs, garage conversions, and backyard cottages. They handle permits, regulatory compliance, and quality construction to maximize living space and rental income potential.
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G.J. Gardner Homes Selma
2020 2nd Street, Selma, CA 93662
G.J. Gardner Homes Selma builds quality ADUs in California with 30+ years experience. Services include detached ADUs, garage conversions & basement apartments. Their 7-step process covers consultation to handover, boosting property value & rental income.
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Coastal ADU Construction
1050 Opportunity Drive, San Francisco, CA 95678
Coastal ADU Construction is a Bay Area design/build contractor specializing in accessory dwelling units. They handle detached ADUs, garage conversions, in-law suites, and granny flats, managing both design and construction while navigating local zoning regulations.
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Other cities in California
What you need to know
Searching for top Basement Conversion ADU Contractors in California? Our directory highlights trusted local professionals who specialize in designing and building accessory dwelling units (ADUs).
Working with a qualified Basement Conversion ADU Contractor in California ensures your ADU project meets local building codes, zoning laws, and permit requirements. Whether you're planning a detached ADU, garage conversion, or backyard cottage, experienced Basement Conversion professionals can guide you through every step.
California homeowners are increasingly investing in ADUs to create additional living space, generate rental income, or support multigenerational living. The Basement Conversion experts featured here bring local expertise and proven experience to help make your project a success.
Browse our listings to find the best Basement Conversion ADU Contractors in California, and get started today.