In Practice
A detached ADU is typically built in the rear yard of a single-family lot, using the portion of the lot behind the primary dwelling. Setbacks apply to detached ADUs and may differ from the setbacks that govern the primary structure — many states have enacted laws limiting the setback distances a city may require for newly constructed detached ADUs. The detached configuration generally allows for the largest ADU footprint and, in most markets, commands the highest rental rate of the three ADU types because the unit is fully independent from the main house.