ADU For You is a Bay Area ADU builder based in Redwood City, offering end-to-end services including design, permits, and construction. Serving 1,000+ clients, they specialize in custom detached ADUs, granny flats, and in-law suites at competitive prices.
read more
AKD Homes is a Bay Area ADU contractor with 20+ years of experience. They offer full-service ADU design and build, including detached ADUs, custom designs, and conversions from Berkeley to San Jose.
read more
Element Home Remodeling is a Mountain View ADU contractor offering full design-build services in Silicon Valley. They specialize in garage conversions, backyard cottages, in-law suites & rental units, serving Palo Alto, Sunnyvale & San Jose.
read more
We Do Construction specializes in ADU garage conversions across the San Francisco Bay Area. Licensed and insured, they handle permitting, 3D planning, construction, and interior design, offering free estimates for homeowners.
read more
Vargas Construction is a California ADU contractor offering detached, attached, garage, junior, and multifamily ADUs. They handle design, permitting, and construction with energy-efficient materials, custom interiors, and full amenities in 2–6 months.
read more
Home by Tom is a Bay Area ADU contractor with 21+ years of experience serving Walnut Creek. They build detached ADUs, attached ADUs, and garage conversions, managing design, permits, and construction for rental income or multi-generational living.
read more
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.
read more
Wellmade is a California prefab ADU builder specializing in panelized accessory dwelling units. Founded in 2020, they've completed 200+ projects, reducing construction waste by 85%. Serving CA, OR, and WA with all-inclusive pricing.
read more
Colibri Kitchen & Bath offers full-service ADU construction in Oakland, handling design, permitting, and building. Services include site assessment, architectural plans, 3D renderings, and complete construction from foundation to finishing.
read more
We are a family-first, boutique residential design & build firm serving the Orinda and East Bay community. We’re not just service providers — we’re your neighbors. We understand the local permitting process, the hillside terrain, the fire-hazard restrictions, and the thoughtful planning needed to create homes that truly work for East Bay families.
read more
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.
read more
Atlas General Construction delivers complete ADU construction for detached, attached, and converted structures. Our team manages every phase of development including zoning research, architectural coordination, structural engineering, Title 24 compliance, permit processing, foundation work, framing, roofing, plumbing, electrical systems, HVAC installation, interior finishes, and final inspections.
read more
Kyvos Construction offers home remodeling & ADU construction in Concord, CA. Services include kitchen & bathroom renovations, room additions, garage conversions, detached & attached ADUs, granny flats, and in-law suites.
read more
ADU Builders Bay Area specializes in detached ADUs, garage conversions, in-law suites & more. Expert ADU contractors offering transparent pricing, full permitting & quality construction throughout the Bay Area.
read moreCastro 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.
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:
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.
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:
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.