For Portland’s single-dwelling zones, there are some code exceptions that allow for more than one dwelling unit on a lot. They apply only in limited geographic locations, like on a corner or next to commercial zones. Accessory dwelling units (ADUs) are allowed citywide, but limited to one per lot and paired only with a single house (i.e., not with a duplex).

The new Comprehensive Plan seeks to enable and encourage “relatively smaller, less expensive units… within a quarter mile of designated centers, corridors with frequent transit, high capacity transit [MAX] stations, and within the 'Inner Ring' [neighborhoods] around the Central City.” Following study of service availability and infrastructure capacity, new housing type exceptions could be adopted in some of these areas. Furthermore, the draft proposal related to historically narrow lots would allow new houses to be built on these narrow lots when they are located near Centers and Corridors.

Use this interactive map to identify single-dwelling residential zones near Centers and Corridors where additional housing types and houses on historically narrow lots could be allowed.