A Junior Accessory Dwelling Unit (JADU), sometimes called a “Carve Out Unit,” is created within the footprint of an existing home. A JADU is limited to 500 sq. ft. and is often made by converting a spare bedroom, attic, or attached garage. Each JADU includes its own kitchen, entrance, and living/sleeping space. Because it reuses existing square footage, the permitting and construction process is usually faster and less costly than other ADU types.

An ADU addition is built by expanding directly from your existing house. This approach adds new square footage and can include one or more bedrooms and bathrooms, depending on the lot size, layout, and local code. Unlike JADUs, these additions are not limited to 500 sq. ft., offering more flexibility in design and function while still remaining connected to the main structure.

Detached ADUs are separate, stand-alone units built on the same lot as the main home. They can be created by converting an existing detached garage or by constructing a new building from the ground up. Detached ADUs typically provide the most freedom in layout, size, and number of rooms, making them a popular option for maximizing rental income, guest housing, or multi-generational living.