What does it cost to build an ADU in Los Angeles? It depends on the type, the size, and the finishes you choose. Use the calculator below to get a realistic ballpark in under a minute. Tell us a few details about your project and you will see an estimated cost range right away, no waiting on a callback.
Ground Up Builders has built ADUs across Greater Los Angeles, Orange County, and Ventura County for over 16 years. The number you get here is a starting point. Your exact price comes after we look at your property.
What drives the cost of an ADU
ADU type: A garage conversion reuses an existing structure and usually costs less than a detached, ground-up build.
Size: Cost scales with square footage, but not in a straight line. Kitchens and bathrooms carry more cost per foot than living space.
Finishes: Standard, mid, and high-end finishes can swing the total meaningfully.
Site conditions: Access, grading, and how far utilities have to run all factor in.
Permitting and plans: Required before any work starts, and the requirements vary by where your property sits across the region.
The estimate from the calculator is an all-in ballpark, not a stripped-down base price with surprises added later. We price the way we build.
ADU types we build
Why homeowners choose Ground Up Builders
- Licensed California general contractor, CSLB #911849, bonded and insured.
- 16+ years building in Greater LA, family-owned.
- 4.7 average across 184+ Yelp reviews.
- Best of Houzz Service (2012, 2022, 2024), IICRC certified, BBB accredited.
Paying for your ADU
An ADU is a large project, and you do not have to fund it all up front. We can walk you through financing options so the monthly number works for you.
frequently asked questions
How much does it cost to build an ADU in Los Angeles?
It depends on the type, size, and finish level. The calculator above gives you a realistic ballpark in under a minute. Your exact price comes after a site visit, since access, utilities, and site conditions all factor in.
What is the difference between a detached, attached, and garage-conversion ADU?
A detached ADU is a standalone unit, an attached ADU is built onto your home, and a garage conversion reuses your existing garage. Garage conversions are often the most budget-friendly, while detached units offer the most flexibility.
Do I need a permit to build an ADU?
Yes. Every ADU in California requires permits, and the exact requirements depend on the jurisdiction your property sits in. We will guide you through what your specific property needs.
Is the calculator estimate my final price?
No. It is a ballpark to help you plan. A detailed, fixed quote comes after we look at your property and confirm the scope.
Can I finance an ADU?
Yes. We can walk you through financing options so the project fits your budget. See our financing page.
Ready for a real number on your ADU?
Run the calculator for a ballpark, then request your detailed quote. Or call us directly at 844-247-6863.