Historic districts in the United States

Historic districts in the United States are designated historic districts recognizing a group of buildings, archaeological resources, or other properties as historically or architecturally significant. Buildings, structures, objects, and sites within a historic district are normally divided into two categories, contributing and non-contributing. Districts vary greatly in size and composition: a historic district could comprise an entire neighborhood with hundreds of buildings, or a smaller area with just one or a few resources.

Historic districts can be created by federal, state, or local governments. At the federal level, they are designated by the National Park Service and listed on the National Register of Historic Places; this is a largely honorary designation that does not restrict what property owners may do with a property. State-level historic districts usually do not include restrictions, though this depends on the state. Historic districts created by local municipalities, however, almost always protect historic properties by regulating alterations, demolition, or new construction within the district.

Much criticism^{[1][2][3][4][5]} has arisen of historic districts and the effect protective zoning and historic designation status laws have on the housing supply.^[1] When an area of a city is designated as part of a 'historic district', new housing development is artificially restricted^[2] and the supply of new housing permanently capped^[1] in area so designated as 'historic'. Critics of historic districts argue that while these districts may offer an aesthetic or visually pleasing benefit, they increase inequality by restricting access to new and affordable housing for lower and middle class tenants and potential home owners.^[6] Housing advocates have argued that the historic designation process has in many places been hijacked by NIMBY homeowners to block housing.^[7]