Accessory Dwelling Units
ADU design, permitting & construction
California opened up what you can build in your own backyard. An ADU can house family, generate rental income, or add long-term value to a property you already own. We handle the whole thing: drawings, plan check, and the build.
Types
Four ways to add a unit
Which one fits comes down to your lot dimensions, your existing structure, and what your city allows. We figure that out before anyone draws anything.
- A
Detached new construction
A standalone unit built in the rear yard. The most flexible option and usually the strongest for rental income, since it functions as a separate home with its own entrance and yard access.
- B
Attached ADU
Built off the existing structure, sharing a wall with the main house. Often the right call on narrow lots where a detached unit won't clear setbacks.
- C
Garage conversion
Reusing an existing footprint. Can be faster and cheaper than new construction, but the existing slab, framing, and utilities determine what's actually possible.
- D
Junior ADU
Under 500 sq ft, created within the walls of the existing home. Lower cost and fewer requirements, with tighter limits on what you can build.
Which one fits your lot goes through the trade-offs and the questions that decide it.
Where you are
ADU rules where you live
State law sets the floor. On top of it every city layers its own setbacks, height limits, and fees, and an address outside a city is governed by the county instead. Put in the address and we'll tell you which one you're under.
Southern California only. Either the city or the ZIP is enough, you don't need both.
For the floor itself, and what changed this January, read what state law lets you build in 2026.