Detached ADU near Castro Valley, CA

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.

Cajigas Construction Inc. is a licensed ADU builder with 35+ years of experience serving Sacramento, Stanislaus, and San Joaquin Counties. Services include detached ADUs, JADUs, garage conversions, new home construction, and REO property services.

Manzanita Design Build is an East Bay ADU contractor specializing in accessory dwelling units. Serving Berkeley, Oakland, Alameda & more. New ADU construction starts ~$300K, 5–8 month build time. Licensed (#1034108) & insured.

Eagle ADU is a licensed ADU builder in Northern California offering three signature models: Eagle Studio ($180K–$220K), Eagle One ($230K–$280K), and Eagle Two ($310K–$360K), with rental income potential up to $4,000/month.

Optivest Build is a licensed general contractor offering ADU construction, garage conversions, home additions, renovations, and new builds. They manage permits, design, and inspections, delivering residential and commercial projects on time and within budget.

Jeff Martinez Construction Inc. builds ADUs in Oakley, CA with 27+ years of experience. Services include detached ADUs, garage conversions, permits, finishing, and landscape integration across Contra Costa County.

ELS Home Builders specializes in ADU design and construction across San Jose, Palo Alto & the SF Bay Area. Services include granny flats, in-law suites, garage conversions & detached ADUs for multigenerational living.

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.

Realty Builders Inc. is a licensed ADU contractor specializing in custom accessory dwelling units, including in-law suites, granny flats, garage conversions & rental units, offering streamlined permitting & guaranteed workmanship.

Element Homes is a California ADU contractor offering full-service design, permitting, and construction. They build detached ADUs, garage conversions, and in-law suites across the Bay Area, with in-house teams, warranties, and free estimates.

The ADU Dudes is a Bay Area & Northern California ADU contractor offering ADU construction, JADUs, garage conversions, home additions & new builds. Licensed under San Andres Construction (#1081083), serving San Jose, Oakland, Fremont & more.

Masterful Construction is a San Mateo ADU contractor serving the Bay Area. They build detached ADUs, garage conversions, and in-law suites, handling design, permits, and construction. Discounts available for military and first responders.

OT Bay Builders is a complete remodeling company with over 40 years of combined experience amongst our team. We’re expert Bay Area ADU builders in San Jose with a customer-first mindset. As a full-service ADU builder, you can trust us to remain by your side from the first consultation to the final walkthrough.

GADI Construction, led by Nadav, specializes in ADU construction, home expansions, garage conversions & granny flats. Known for detailed planning, clear communication & professional client guidance throughout every project phase.

Bay Area design-build ADU specialists. One project, one point of contact — design, engineering, permitting, and construction from start to finish. CSLB #1130783.