what is an adu

ADU stands for "Accessory Dwelling Unit". It is a secondary housing unit on a single-family residential lot that is either attached or detached from the main house. An ADU is a self-contained apartment, cottage, or small residential unit that has complete independent living facilities for one or more persons. It is also known as a granny flat, in-law unit, casita, or backyard cottage. ADUs are significantly smaller than the average US house and tend to be one of two units owned by one owner on a single-family residential lot. They are often built with cost-effective one- or two-story wood frames, which are less expensive than other construction types. ADUs can provide as much living space as apartments and condominiums and work well for couples, small families, friends, young people, and seniors. The regulations and zoning requirements for ADUs vary widely by state and municipality.