Cost of accessory dwelling unit

Looking for cost of accessory dwelling unit in San Jose, CA? Call AccessoryDwellingUnit Solutions for a contact a provider — no obligation. Licensed adu builders serve San Jose and the surrounding area, and you'll get straight answers on timing and what affects the price.

Last updated: September 24, 2026

What affects the price

Building an ADU involves several moving parts that shape your total budget. The biggest factor is whether you choose a prefabricated unit or a custom build on-site. Site preparation is also significant; if your land requires extensive grading, utility trenching, or foundation work, costs will climb. Your choice of finishes—like kitchen cabinetry, flooring, and siding materials—also shifts the bottom line. We help you navigate these variables to find a setup that fits your property. Exact pricing confirmed free on the call.

About this service

The total price for an ADU depends on several moving parts, including the square footage, your foundation type, and local labor rates. Choosing high-end finishes or complex site prep will naturally increase the budget, while standard layouts help keep things manageable. Exact pricing confirmed free on the call.

Frequently asked in San Jose

What are the disadvantages of ADUs in San Jose?

While ADUs offer many benefits, potential drawbacks can include increased utility costs for your property and the need for careful planning regarding privacy for both you and your ADU occupants. Neighbors might also have concerns, though city ordinances aim to address these. Understanding these points upfront is key to a successful project.

How much does an ADU cost in California?

The cost of an ADU in California, including San Jose, varies significantly based on size, materials, and site preparation. Detailed site assessments and custom quotes are essential for an accurate figure.

What are the rules for ADUs in California?

California has state-level laws promoting ADUs, generally streamlining approvals and limiting local restrictions. Cities like San Jose must comply, often setting specific setback requirements and design guidelines. Understanding these state and local nuances is crucial for your project's success.

Is an ADU allowed in Maryland?

This service focuses on California. While Maryland has its own ADU regulations, we specialize in the California market and its specific requirements for cities like San Jose. For Maryland, you would need to consult local resources there.

While there have been programs and grants aimed at supporting ADU development in California, specific details and availability can change. It's important to research current state and local initiatives that might offer financial assistance for your San Jose ADU project.

What are the rules for ADU in California?

California's ADU laws generally encourage their construction by setting maximums on impact fees and minimum sizes, while also limiting owner-occupancy requirements in some cases. Local jurisdictions, including San Jose, then add their specific zoning and design standards. Reviewing these together is vital.

Also serving nearby: Burbank · Santa Clara · Sunnyvale · Fremont · Hayward

All cities in California →

More on this: HUD ADU resources — ADU policy and financing research.

Service area details

969,655residents

5,449per sq mile

8ZIP codes served

Serving all of San Jose — population 969,655; about 5,449 residents per square mile across 177.9 sq mi. ZIP codes covered include 95025, 95101, 95103, 95106, 95108, 95109, 95110, 95111.

Neighborhoods served in San Jose: Cambrian Park, Willow Glen, Alum Rock, Berryessa, Downtown San Jose, The Rose Garden — and every surrounding area.