In the law regulating historic districts
in the United States
, a contributing resource
or contributing property
is any building, structure, or object which adds to the historical integrity or architectural qualities that make the historic district, listed locally or federally, significant. Government agencies, at the state, national, and local level in the United States, have differing definitions of what constitutes a contributing property but there are common characteristics. Local laws often regulate the changes that can be made to contributing structures within designated historic districts. The first local ordinances
dealing with the alteration of buildings within historic districts was in Charleston, South Carolina in 1931.
Properties within a historic district fall into one of two types of property: contributing and non-contributing. A contributing property, such as a 19th Century mansion, helps make a historic district historic, while a non contributing property, such as a modern medical clinic, does not. The contributing properties are key to a historic district's historic associations, historic architectural
qualities, or archaeological
qualities. A property can change from contributing to non contributing and vice versa if significant alterations take place.
According to the National Park Service
, the first instance of law dealing with contributing properties in local historic districts
occurred in 1931 when the city of Charleston,......