Accessory dwelling unit

An accessory dwelling unit (ADU) — also sometimes known as an additional dwelling unit — is a second housing unit on the same lot as a single-family home, which has its own kitchen, bathroom, bedroom and entrance. These can be entirely separate structures, or they can be converted spaces such as a basement suite or an apartment above a garage. ADUs are often used as a separate space for a family member to call home, which is why they are sometimes called in-law suites. However, you don’t have to be related to the single-family home owner to live in an ADU. ADUs are not permitted everywhere, but they have become a popular way to earn rental income in places they are allowed, especially in expensive areas like California.