Commercial overlay

A commercial overlay is a commercial district mapped as a strip along shopping streets within residence districts, reaching a stated depth from the street it follows. Within the strip, local retail and service uses become lawful on lots that remain residentially zoned underneath; outside it, the residence district continues unmodified. The overlay carries its own rules for the commercial floor area and its parking.

Overlays are the workhorse of the neighborhood shopping street, and a standard source of split lots: a lot deeper than the overlay's mapped depth is divided by construction, its front portion carrying commercial permissions its rear portion lacks. Mapping is parcel-precise, so whether a specific lot is inside is a geometry question, not a neighborhood impression.