200 “H” Street
Antioch, CA 94531
Building Services Division
Tel: (925) 779-6159
Code Enforcement Division
Tel (925) 779-7042
An Accessory Dwelling Unit (ADU) is a complete, independent residential dwelling that is located on a lot with a proposed or existing residence or multifamily residences in a zoning district that allows single and multifamily uses. ADUs are sometimes also called granny units or second units.
Another type of ADU is a Junior ADU (JADU), which is a small unit (500 square feet or less in size) created from a portion of a single-family dwelling. These units can have their own bathrooms or share with the main residence. An efficiency kitchen is required.
Recent changes to California law have relaxed zoning standards for ADUs throughout the state. The ADU Summary Table, below, provides information on the zoning standards and regulations including setbacks, maximum square footages, and height limits.