what is a historic structure 
a historic structure is a sub category of a historic property as designated by the national register of historic places referred to as the national register in casual conversation a historic structure refers to a building or other structure such as a bridge mine canal ship highway or locomotive that is significant because of its link to an important period in the past but the official designation distinguishes a structure as being distinct from a human shelter understanding a historic structurehistoric structures may have unique architectural features or political meaning areas with a large number of historic structures may be designated as historic districts 1 property owners in historic districts generally face special rules and restrictions on the maintenance of and alterations to the property sometimes grant money or tax credits are available to restore historic structures in disrepair 23a historic structure is an official designation by the national register of historic places the national register designates historic properties including buildings structures objects sites and districts historic properties including historic structures can be officially registered as historic with the national park service and placed on the national register of historic places by petitioning the state historic preservation office where the structure is located the petition contains information about the property s historic and current functions architectural classification and materials and other details to be listed the property must meet at least one of four key national register criteria 42the number of national historic landmarks in the united states 5the four criteria of the national registerthe national register of historic places has established four objectives specific criteria that can qualify a structure to be designated as historic from the national register documentation structures are historic a structure only has to fit one of these criteria to be designated as a historic structure by the national register the intent of these criteria is to ensure that structures that have some kind of cultural and historical relevance are preserved but the designation is not to be overused for a building that is simply a certain age but is not otherwise significant 6