A garage conversion ADU in Los Angeles costs about $120,000 to $150,000 in 2026 for a typical 350 to 400 square foot unit, including drawings, permits and construction. Garages with a sound slab and easy utility access sit at the low end. Ones needing a new slab, structural work or long utility runs cost more.
What actually changes
The garage door opening gets framed in and takes a window or a door. The slab usually gets resurfaced or replaced, because garage slabs slope toward the door and have no moisture barrier under them. Walls and ceiling get insulated and drywalled. Then it needs a bathroom, a kitchen, its own electrical, plumbing, a mini-split for heating and cooling, and an escape window. If the garage shares a wall with the house, that wall has to be built to a fire rating.
You do not have to replace the parking
State law bars cities from requiring replacement parking when you convert a garage into an ADU. You can also keep the setbacks the garage already has, even if they are tighter than what a new building would be allowed.
How long it takes
Drawings take 4 to 6 weeks, permits 2 to 3 months, and construction 3 to 5 months. Call it nine months to a year from first conversation to a tenant with keys.
Los Angeles County figures, reviewed 2026-10-29 by America General Contractors, California contractor licence CSLB 1083262. Planning ranges, not a quote, and not legal advice. We confirm the current rules for your parcel before anything gets drawn.
Related questions
- How much does an ADU cost in Los Angeles?
- What is a garage conversion ADU?
- What are the ADU setback and height rules in Los Angeles?
