Waltco Development · Updated October 2026
Accessory dwelling units are one of the most common projects on Los Angeles lots. Here are the types, how permits work, and what to settle before construction starts.
The four kinds of ADU
California law recognises several ways to add a unit to a single-family lot:
- Detached ADU: a separate building in the yard.
- Attached ADU: an addition that shares a wall with the house.
- Garage conversion: an existing garage turned into living space.
- Junior ADU (JADU): a unit of up to 500 square feet created inside the existing home.
Permits
In the City of Los Angeles, ADU plans are reviewed and permitted by the Department of Building and Safety (LADBS). Santa Monica, Malibu, Manhattan Beach and Redondo Beach review ADUs through their own departments under the same state law. Lots in the coastal zone can need additional review.
What to settle before construction
- How the unit will be used — rental, family, office — which shapes layout and finishes.
- Utilities: whether the existing electrical service and sewer line can carry the new unit.
- Access and parking for construction on your lot.
- Who prepares the plans: a designer or architect draws them; we build from approved plans.
Questions
Frequently asked questions
- Can I rent out my ADU?
- Generally yes, subject to state and local rules on rental terms. Check current City of Los Angeles rules before you sign a lease.
- Does Waltco design ADUs?
- We build from plans prepared by your designer or architect and coordinate with them through plan check and construction.
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