Attached ADU near Castro Valley, CA

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.

DevArt8 Builders specializes in ADU construction in Gilroy, offering floor plans from 350–650 sq. ft. They handle permits, ensure zoning compliance, and build detached ADUs, attached units, and garage conversions tailored to each property.

BUILD 33 (CSLB #1051529) is a licensed general contractor based in Cupertino, CA, serving California, Arizona, Nevada, and Louisiana. They offer home additions, flooring, painting, plumbing, electrical, and more. Free quotes available.

Bay Villa Builders brings over 50 years of combined experience in crafting expertly designed ADUs that enhance both your home's functionality and its value. An Accessory Dwelling Unit, or ADU, serves as an additional living space on your property.

American Builders is a San Francisco ADU contractor specializing in garage conversions, detached units, in-law suites & basement conversions. They handle permits, zoning, and deliver code-compliant accessory dwelling units on time and on budget.

UDA ADU is a California ADU contractor specializing in detached ADUs, garage conversions, JADUs, and in-law suites. They handle design, permitting, and construction, offering homeowners a streamlined, full-service ADU building experience.

Custom ADU construction and remodeling services focused on creating functional, comfortable living spaces with quality craftsmanship and reliable workmanship.

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.

Ingenious General Construction is a BBB-certified, licensed contractor in Walnut Creek, CA, serving the East Bay. With 20 years of experience, they offer ADUs, kitchen & bathroom remodeling, home additions, pool construction, and landscaping.

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.

At ADU San Mateo, we combine architectural insight, construction experience, and deep knowledge of Bay Area zoning laws to deliver high quality accessory dwelling units from design through move in. Our mission is simple: to make building your ADU clear, fast, and stress free.

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.

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.

At Ingenuity Construction Group, we specialize in crafting exceptional Accessory Dwelling Units (ADUs) that blend seamlessly with your existing property. With over 20 years of experience, our dedicated team ensures each ADU project is completed with meticulous attention to detail and superior craftsmanship.