ADU types

Five ways to add a home

Most lots can hold more than one of these. The cheapest is often not the one people picture.

Pick the one your lot wants

What each one is and who it suits.

The garage becomes a home. No new setbacks, no replacement parking, and usually the least costly full-size unit.

Up to 500 sq ft carved out of the house you have. The smallest budget and the simplest permit.

A new wing that shares a wall with the house and has its own front door. Good for narrow lots.

Its own building in the back yard. The most privacy of any type.

Keep the parking and the yard, add a home upstairs.

Compare

Typical timelines from the first call to move-in.

Type	Key rule	First call to move-in
Garage Conversion	0 replacement parking spaces	6-10 months
Junior ADU (JADU)	500 sq ft maximum size	4-8 months
Attached ADU	4 ft side and rear setbacks	10-16 months
Detached ADU	4 ft side and rear setbacks	12-18 months
Above-Garage and Second-Story ADU	Up to 25 ft height when attached	14-20 months

The rules

State law sets a floor no California city can go below.

Send the address. We'll tell you which of these fit your lot.