Cost to build accessory dwelling unit in California
Last updated: September 24, 2026
Thinking about an accessory dwelling unit in California? We serve Anaheim, Riverside, Moreno Valley, Oxnard, Elk Grove, Santa Rosa, and many other cities. California's climate is varied, but generally mild. This allows for a longer building season compared to other states.
Choose your city
Building an ADU in California is popular. State laws encourage ADUs, making permitting more streamlined. Local rules still exist in areas like Anaheim and Riverside. We help you navigate these requirements smoothly. Understanding your city's specific zoning is crucial.
Common questions
What is the cheapest way to build an ADU?
What does ADU stand for?
ADU stands for Accessory Dwelling Unit. It's a second, smaller home on your property. Think of it as a backyard cottage or garage apartment. These units add living space and value.
Are ADUs allowed in California?
Yes, ADUs are widely allowed in California. State laws make them easier to build. Local rules in cities like Riverside still apply. We help you understand and comply with these regulations.
What is the most expensive part of building an ADU?
Foundation work and structural framing are often the most costly. Plumbing and electrical hookups add significant expense. Labor costs and chosen finishes also influence the total price. We provide a clear quote for your project.
How much does it cost to build an ADU in California?
What is the cheapest way to build an ADU?
Useful reference: HUD ADU resources — ADU policy and financing research.