Can ADU's be sold separately? No, ADU's cannot be sold separately except in few cases. The owner has to sell the primary property along with ADU. In the following article we will look at it in more detail. Accessory dwelling units: what they are and why people build them An accessory dwelling unit is a really simple and old idea: having a second small dwelling right on the same grounds (or attached to) your regular single-family house, such as: an apartment over the garage a tiny house (on a foundation) in the backyard a basement apartment People build them for lots of reasons, but the most common goals, according to one study, are gaining income via rent and housing a family member. Flexibility in housing makes sense for environmental, lifestyle, and financial reasons. Though many people buy houses and live in them for decades, their actual needs change over time. It is not uncommon to see developer splitting primary home and ADU to sell in parts. Though, this is pretty rare..However, it is not ruled out.