ADU Contractor in San Jose: What to Know Before Building an ADU

An accessory dwelling unit, also called an ADU, can add flexible living space, rental potential, or room for family members. But before starting an ADU project, homeowners should understand the planning, design, permit, and construction process.

Bay Stone Builders helps Bay Area homeowners with remodeling, additions, ADUs, and full construction projects. A successful ADU starts with a clear plan, realistic budget, and the right contractor team.

Know What Type of ADU You Want to Build

ADUs can be built in different ways, including garage conversions, detached backyard units, attached additions, or interior conversions. Each option affects layout, utilities, access, privacy, cost, and permit requirements.

Plan Utilities Early

Plumbing, electrical, heating, cooling, water heating, sewer connection, and laundry needs should be reviewed early. These items can affect the design and budget more than many homeowners expect.

Permits Are a Big Part of the Process

Most ADU projects require plans, permit review, inspections, and coordination between design and construction. Working with a licensed general contractor can help keep the project organized from the first site visit through final inspection.

Budget Beyond the Shell

An ADU budget should include foundation or slab work, framing, roofing, insulation, windows, doors, electrical, plumbing, HVAC, drywall, flooring, cabinets, bathroom work, kitchen area, exterior finishes, and inspections. Planning the full scope helps avoid surprises.

Talk to Bay Stone Builders

Bay Stone Builders serves San Jose, Campbell, Willow Glen, Los Gatos, Santa Clara, Cupertino, Sunnyvale, and nearby Bay Area communities. If you are planning an ADU, garage conversion, addition, or remodel, call or text 669-272-9362 to discuss your project.