Last updated: September 24, 2026
What affects the price
Building an ADU is a major project, and the final bill depends on a few key things. Site prep is a big factor; if your land is sloped or needs extensive utility connections, costs go up. The materials you choose—from siding to kitchen finishes—also change the math significantly. Whether you’re building a detached unit or converting an existing garage shifts the permit requirements and structural work needed. We provide exact pricing confirmed free on the call.
About this service
Total ADU costs are driven by the foundation type, the complexity of plumbing and electrical runs, and your choice of fixtures. We provide a clear breakdown of where your money goes so you know exactly what you are paying for from day one. Exact pricing confirmed free on the call.
Frequently asked in San Jose
What are the disadvantages of ADUs?
While ADUs offer many benefits, potential disadvantages include upfront construction costs and the time it takes to secure permits in San Jose. You'll also need to consider ongoing maintenance and potential impacts on your current property's yard space. It's important to weigh these factors against the advantages for your specific situation.
How much does an ADU cost in California?
The cost of an ADU in California, including San Jose, varies widely based on size, materials, and site conditions. Factors like foundation type, finishes, and whether you need to upgrade utilities significantly influence the final price. Getting a detailed quote is the best way to understand the investment for your specific project.
What are the rules for ADUs in California?
California has state laws that streamline ADU development, but local San Jose ordinances also apply. These rules cover aspects like minimum lot size, setbacks, and parking requirements. Understanding both state and local zoning is essential to ensure your ADU project complies with all regulations.
Is ADU allowed in Maryland?
This question is for San Jose, California. Maryland has its own set of ADU regulations that differ from California's. If you are in Maryland, you'll need to consult with local authorities there regarding ADU permissibility and building codes.
What are the rules for ADU in California?
California ADU rules generally allow for ADUs on most single-family and multi-family lots, with specific size limitations and development standards. Local jurisdictions like San Jose implement these state guidelines with their own zoning ordinances. Key considerations include fire safety and utility connections.
While there have been various grant programs and incentives for ADUs in California, specific details and availability can change. It's best to inquire about current programs during your consultation to see if any financial assistance options apply to your San Jose ADU project. The availability of such grants is often tied to specific income levels or project types.
Also serving nearby: Burbank · Santa Clara · Sunnyvale · Fremont · Hayward
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
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: Willow Glen, Almaden Valley, Japantown, Downtown San Jose, Campbell, Santa Clara — and every surrounding area.
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