Detached ADU near Castro Valley, CA

Spruce ADU Builders is a licensed ADU contractor in Union City offering expert accessory dwelling unit construction. Services include granny flats, in-law suites, and custom ADUs with free consultations, transparent pricing, and a 100% satisfaction guarantee.

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.

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.

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.

LiveLarge Home is a California prefab ADU builder offering full-service solutions from permits to final inspection. Build times start at 4–6 weeks, with fixed pricing from $412/sq. ft. Models range from studios to 2-bed/2-bath units with premium finishes.

YCD Studio is a Bay Area architecture firm specializing in ADU design and permits in Moraga and the Lamorinda area. Services include detached ADUs, garage conversions, and JADUs, with expertise in WUI standards and local fire district requirements.

ON Design & Remodeling is a Bay Area ADU builder offering home additions, garage conversions, granny flats, and in-law suites. They help homeowners expand living space, boost property value, and generate rental income.

Mountain Top Construction is a Bay Area ADU builder serving San Rafael, San Francisco, and Las Vegas. They specialize in detached ADUs, backyard cottages, granny flats, and in-law suites, managing design, permitting, and construction.

ProStruct Engineering offers ADU structural engineering services across California, providing permit-ready plans and calculations for detached ADUs, garage conversions, granny flats, and more, with a 2–3 week turnaround.

Bao-Tran Builders Inc specializes in ADU construction, including detached ADUs, granny flats, JADUs, garage conversions & multi-unit properties. Expert ADU contractor delivering functional, high-quality housing solutions for property owners.

Leon's Construction Inc. offers ADU construction services in Escondido, Encinitas, and San Marcos, CA. They build backyard cottages, basement apartments, tiny homes, and more using durable, energy-efficient materials.