Historic district

A historic district is a mapped area designated by the Landmarks Preservation Commission for its collective character: within the boundary, every property is regulated — exterior alterations, demolition, and new construction all need Commission approval — whether or not the individual building is architecturally distinguished. The district, not the building's merit, is the trigger.

Districts are drawn through public designation processes and documented in designation reports describing what the area's character consists of. For owners and buyers, district membership is a parcel-checkable fact with permit consequences on essentially any exterior work; for analysis, it is one of the mapped layers — like zoning and flood — that a lot either sits inside or does not.