A junior accessory dwelling unit (JADU) is a separate California statutory category. It is created within the walls of a proposed or existing single-family residence under a local ordinance; it is not interchangeable with every unit called an ADU. California Government Code section 66333 limits a local JADU ordinance to one JADU on a qualifying lot and sets specific owner-occupancy and rental conditions.
When owner occupancy applies
If the JADU shares sanitation facilities with the primary home, the local ordinance must require the owner to live in the single-family residence. The owner may live either in the remaining part of the home or in the JADU. The statute does not require owner occupancy when the JADU has separate sanitation facilities. It also states an exception for an owner that is a governmental agency, land trust, or housing organization.
These conditions are tied to the JADU pathway. Do not apply them automatically to a detached ADU or to a property in another state. Check the city’s or county’s current JADU ordinance, permit, and the actual sanitation layout before relying on the rule.
Rental terms and separate sale
California requires a JADU rental term to be longer than 30 days. A JADU is therefore not a route for stays of 30 days or less. If renting the unit, verify the local rental and occupancy rules as well as the state minimum term.
A local JADU ordinance must also require a deed restriction that prohibits selling the JADU separately from the single-family residence and runs with the land. Review the recorded restriction and title before a transfer or financing decision. Separate sale, lawful construction, building-code compliance, and occupancy approval are different questions.
The California Department of Housing and Community Development’s March 2026 handbook summarizes the current JADU sanitation, owner-occupancy, and rental-term rules. Use it with the statute and the local ordinance; neither decides the status of an individual property.