An Accessory Dwelling Unit (ADU) is a secondary residential unit added to a property with an existing or planned single-family home. ADUs are sometimes referred to as granny flats, in-law units, second units, backyard homes, cottages, or basement apartments. While ADUs come in many forms and sizes, they always include a kitchen, bathroom and sleeping area.
Homeowners build ADUs on their properties for a variety of reasons, such as housing a family member, gaining rental income, increasing overall property value, and adding to the affordable housing stock in their community. ADUs are affordable to build because owners don’t have to purchase additional land, and recent revisions to California State Law have made it easier to construct ADUs on single-family properties.
There are many different types of ADUs homeowners can build on their properties. While you may build a new unit entirely, converting an existing garage or room inside your home is the easiest way to add an ADU to your property. In fact, 45% of all ADUs constructed since 2017 in the City of LA are conversions. Read below to learn more about the different types of ADUs and various requirements associated with each.