An Accessory Dwelling Unit (ADU) is a secondary dwelling on a typical single-family lot that can be attached to the main dwelling or detached at the rear of the property. They are allowed in the R-50, R-60, R-85, RS-17, RM-18, RM-22, RM-43, and PO zoning districts.
These smaller units are part of the "missing middle" housing types that fill the gap between single-family and large-scale, multi-family homes. ADUs promote the city's values of diversity and affordability by providing rental housing options within single-family neighborhood settings.
One ADU per primary dwelling unit is possible and must comply with the regulations of the zoning district in which it is located. Other considerations are found in Unified Development Ordinance Section 6.8.3 - Standards for Specific Accessory Uses.
ADUs are not the same as duplexes or walk-up flats, which are also allowed in all residential zoning districts but have different requirements.