Handbook 4000.1, 12/30/2016, page 499
An Accessory Dwelling Unit (ADU) refers to a habitable living unit added to, created within, or detached from a primary one-unit Single Family dwelling, which together constitute a single interest in real estate. It is a separate additional living unit, including kitchen, sleeping, and bathroom facilities.
An ADU may or may not have separate meters or a separate means of ingress and egress. The living area of the ADU may not be included in the GLA of the house. A finished basement that constitutes a separate living unit is an ADU (Handbook 4000.1, 12/30/2016, page 500).
The living area over the garage is an accessory dwelling unit (ADU) and was recognized as a separate line item on the sales grid. (Handbook 4000.1, 12/30/2016, page 499-500)
Accessory Unit in Basement
The basement is an accessory dwelling unit (ADU). For consistency in adjustments, it was recognized as finished basement on the sales grid. (Handbook 4000.1, 12/30/2016, page 499-500)