Detached accessory dwelling unit — Santa Clara, CA
Last updated: September 24, 2026
What affects the price
Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.
About this service
A detached ADU is a standalone building separate from your main house, like a cottage or a converted garage. You choose this style if you want maximum privacy for your tenants or family members. Because it requires its own foundation and utility lines, it is a significant construction project. Exact pricing confirmed free on the call.
Frequently asked in Santa Clara
What's involved in adding an accessory dwelling unit in Santa Clara?
How do I find a local ADU contractor in Santa Clara?
What are the rules for accessory dwelling units in Santa Clara?
Can you help me get an accessory dwelling unit permit in Santa Clara?
What are the benefits of accessory dwelling units for Santa Clara homeowners?
What is the process for a detached accessory dwelling unit in Santa Clara?
How much does an accessory dwelling unit cost in Santa Clara?
Also serving nearby: Sunnyvale · Burbank · Fremont · San Jose · Hayward
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Santa Clara — population 131,062; about 7,170 residents per square mile across 18.3 sq mi. ZIP codes covered include 95050, 95051, 95052, 95053, 95054, 95055, 95056.
Neighborhoods served in Santa Clara: Franklin Square, Homestead, Old Quad, Rivermark, Parkside — and every surrounding area.
Areas we serve
Browse by state, then city.