ADU Contractors near Castro Valley, CA
Valley Home Builders inc.
3466 Edward Avenue, Santa Clara, CA 95054
25.5 miles
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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DSA Architects
1107 Virginia Street, Berkeley, CA 94702
16.6 miles
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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Home Revive Builders
15559 Union Ave #234, Los Gatos, CA 95032
33 miles
Home Revive Builders is a licensed ADU contractor in the Bay Area, CA, specializing in garage conversions, detached ADUs, in-law suites, and more. Full-service projects include design, permits, plumbing, electrical, and finishing.
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Jaws Construction Services
14000 Kelso Road, Byron, CA 94514
26 miles
Jaws Construction Services builds ADUs, garage conversions, and JADUs. They handle permits, HOA coordination, and offer site-built or prefab options. East Bay ADUs rent for $1,500–$3,500+/month, potentially boosting property value.
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Barzel Builders
4039 Transport Street, Palo Alto, CA 94303
19.7 miles
Roof and Realm
2245 Vía De Mercados, Concord, CA 94520
18.6 miles
Roof and Realm is a California-based steel-framed modular home and ADU builder offering fire, earthquake, and wind-resistant structures. Their eco-friendly builds use 98% recyclable materials, generate minimal waste, and support solar-ready, Net Positive energy designs.
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Anura Design
367 Civic Drive, Pleasant Hill, CA 94523
18.6 miles
Anura Design specializes in ADU design, offering styles from modern farmhouse and contemporary steel to Mediterranean stucco. Their interiors feature open-concept layouts, natural wood tones, and refined finishes tailored to compact, functional living spaces.
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California Bay Builders & Remodeling
2150 N 1st Street Suite 400, San Jose, CA 95131
24.2 miles
Bay Area design-build ADU specialists. One project, one point of contact — design, engineering, permitting, and construction from start to finish. CSLB #1130783.
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Barcci Builders
16185 Los Gatos Boulevard, Los Gatos, CA 95032
33.3 miles
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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Crane Construction
1910 North Main Street, Walnut Creek, CA 94596
13.5 miles
Crane Construction is a licensed Bay Area general contractor based in Walnut Creek, CA. They specialize in design-build projects, ADUs, garage conversions, remodeling, and new construction for residential and commercial clients. Free estimates available.
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Haus+
Corte Madera, CA 94925
29.5 miles
Haus+ is a Bay Area ADU builder offering turnkey accessory dwelling units for California homeowners. They handle design, permitting, and construction using a panelized hybrid method, with all-inclusive upfront pricing and in-house financing available.
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Tucan Builder
50 Woodside Plaza, Suite 814, Redwood City, CA 94601
19.6 miles
Tucan Builder is a family-owned general contractor in Redwood City, CA, serving San Mateo County. Specializing in ADU construction, room additions, kitchen remodeling, and home renovations, they bring 30+ years of combined experience.
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Mola Construction & ADU
1294 Caldwell Court, Sunnyvale, CA 94087
24.9 miles
Mola Construction is a trusted ADU builder in San Jose with 20+ years of experience. They offer custom ADUs, kitchen remodels, home additions, and full remodeling services across the Bay Area, ensuring California code compliance.
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prefabADU
1111 Western St, Fairfield, CA CA 94533
39.1 miles
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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Sigura Construction, Inc.
1290 Reamwood Avenue, Sunnyvale, CA 94089
21.1 miles
Sigura Construction, Inc. builds ADUs & garage conversions in Silicon Valley. Licensed, A+ BBB rated, Diamond Certified 18+ years. Serving Menlo Park, Palo Alto, Atherton & more. Free estimates available.
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Other cities in California
What you need to know
ADU Contractors in Castro Valley: Building in Alameda County's Unincorporated Community
Castro Valley is a unique location for ADU construction because it is an unincorporated community governed by Alameda County rather than an independent city. This means that homeowners looking to build an Accessory Dwelling Unit must work with the Alameda County Planning Department and follow Alameda County's specific zoning codes and building regulations. Experienced ADU contractors in Castro Valley understand this distinction and are well-versed in navigating county-level permitting processes, which differ significantly from those of neighboring incorporated cities like San Leandro or Hayward.
Key ADU Regulations Castro Valley Contractors Must Follow
Because Castro Valley falls under Alameda County jurisdiction, ADU contractors must comply with the county's ADU ordinance, which aligns with California state law but includes local nuances. Some important regulatory considerations include:
- Setback requirements: Detached ADUs in unincorporated Alameda County typically require a minimum 4-foot rear and side yard setback.
- Maximum ADU size: Detached ADUs can generally be up to 1,200 square feet, depending on lot size and zoning designation.
- Height limits: Detached ADUs are typically limited to 16 feet in height, though this can vary based on proximity to the primary dwelling.
- Owner-occupancy rules: California state law has suspended owner-occupancy requirements for ADUs through January 1, 2025, which applies to Castro Valley properties as well.
- Utility connections: Separate utility connections may be required, and contractors must coordinate with East Bay Municipal Utility District (EBMUD) for water and sewer services.
Why Hire a Local ADU Contractor in Castro Valley?
Hiring a contractor with direct experience in Castro Valley and Alameda County is essential for a smooth ADU project. Local ADU contractors are familiar with the Alameda County Building Services Agency, which handles permit applications, inspections, and plan checks. They understand the typical timelines, required documentation, and how to address common issues that arise during the approval process. Castro Valley's hillside terrain in many neighborhoods also presents unique grading and foundation challenges that experienced local contractors are equipped to handle.
Types of ADUs Popular in Castro Valley
Castro Valley homeowners are increasingly choosing ADUs to address the Bay Area's housing demand and to generate rental income. The most popular ADU types in the area include:
- Detached ADUs: Standalone structures built in the backyard, ideal for larger lots common in Castro Valley's residential neighborhoods.
- Garage Conversions: Converting existing attached or detached garages into livable ADU space.
- Junior ADUs (JADUs): Units up to 500 square feet created within the existing footprint of the primary home.
Start Your Castro Valley ADU Project Today
Working with a qualified ADU contractor in Castro Valley ensures your project meets all Alameda County requirements while maximizing your property's potential. From initial design and permitting through final inspection, the right contractor will guide you every step of the way, helping you add value to your home in one of the East Bay's most desirable communities.