A secondary dwelling unit built on a residential lot — a complete independent home with its own kitchen, bathroom, and entrance, sharing the lot with the primary residence.
California state law requires cities to approve, without discretionary review, an ADU that meets the statutory conditions on a lot with a proposed or existing single-family home in a residential or mixed-use zone. Sometimes called granny flats, in-law units, casitas, secondary dwellings, or backyard cottages — all the same thing under the law.
Part of the BackyardADU California ADU Glossary — plain-English definitions of the regulatory, construction, and financing terms you'll encounter during a California ADU project.