Best Builders in San Jose, CA

Custom ADU builders in San Jose, California with 30+ years of combined experience.

Santa Clara ADU Builders is a certified ADU builder company in San Jose.

prefabADU, based in the Bay Area of California, aims to make affordable housing actually affordable by providing ADU kits and resources for homeowners to build their own ADUs.

ADORE Homes ADUs is a San Jose, California-based ADU construction company operating under the ADORE Homes brand, specializing in prefabricated manufactured accessory dwelling units delivered and installed across the Bay Area. The company is headquartered at 2181 Woodard Rd in the Campbell/San Jose area and is led by CEO Tomer Ginsberg. The firm builds HUD-approved manufactured ADUs off-site and delivers finished units to customer properties, covering the full process from permitting and site prep through unit installation and optional tenant placement. ADU models range from approximately 420 to 1,196 square feet with studio through three-bedroom layouts, including named models like the ADORE Horizon 972, ADORE Crema 667, and ADORE Crema 660. Pricing starts around $420 per square foot with average total project costs near $245,700. ADORE Homes holds active California General Building Contractor License #1145340 and ranks in the 93rd percentile of California contractors on BuildZoom based on 14 permitted projects since 2023. The company serves over 40 Northern California cities including San Jose, Oakland, San Francisco, Fremont, San Mateo, Palo Alto, and Sunnyvale. Best for Bay Area homeowners who want an all-inclusive, low-hassle path to a new backyard ADU. Their off-site manufacturing model delivers speed and quality control advantages over traditional site-built construction, though total project timelines including permitting typically run 12-20 months.

Acton ADU is a Bay Area-based design-build firm with over 35 years of construction experience, specializing exclusively in accessory dwelling units. Founded by Stanley Acton and headquartered in Campbell, CA, the company handles every phase in-house: feasibility assessment, custom design, permitting, construction, and warranty. All units are site-built to California residential standards — not prefab or modular. In San Jose specifically, Acton ADU holds the distinction of having the most pre-approved ADU floor plans on file with the city, significantly reducing permitting timelines for homeowners. Their Build Ready series offers standardized floor plans with predictable costs, while the Signature Series caters to homeowners who want elevated finishes and premium design. Their process is fully turn-key — they manage permit navigation across 40+ Bay Area jurisdictions, offer designer-curated interior packages, and provide financing guidance. Bay Area detached ADU costs typically run $225K–$475K depending on size, with a total project timeline of 9–14 months including permitting. They serve 40+ cities across the South Bay, Peninsula, and East Bay. Customers consistently praise the company for transparent communication, professional project management, and their expertise navigating San Jose's permitting process. Best suited for San Jose homeowners seeking a completely hands-off ADU build with pre-approved city plans.