Garage conversion ADU – requirements and floor plans
Turn a garage into an ADU: what California allows, egress windows, kitchen and bath layout, and the drawings you need.
Reading time about 6 minutes
Why garages are popular
A garage already has a foundation, walls and a roof. In California, converting an existing garage can't be denied for setbacks, and cities can't require replacement parking for the lost spaces.
What has to change
To become a home, the garage typically needs:
- Insulated walls, ceiling and often a raised floor.
- An egress window in the sleeping area (at least 5.7 sq ft opening).
- A kitchen and a bathroom with new plumbing.
- A normal entry door instead of the garage door.
- Smoke and CO alarms.
A typical layout
A two-car garage fits a studio or one-bedroom: kitchen along one wall, bathroom in a corner and living space where the garage door used to be. Draw both the existing garage and the new layout.
Frequently asked questions
Can I keep the garage door?
Some cities allow it if the wall behind is insulated. Most owners replace it with a wall, window and door.
How long does a permit take?
In California, a complete application must be approved or denied within 60 days.
Codes and zoning vary by state, county and city. Always check with your local building department and HOA before you build.