Homes and buildings over fifty years old are often included in historic zones. These zones have regulations, which prevent the alteration of the structures from the original conditions, although there are allowances for repair and restoration in keeping with the historic plan. Frequently, buildings in these areas can qualify for governmental tax incentives.

The National Register of Historic Places is the U. S. official list of cultural resources worthy of preservation. Authorized under the National Historic Preservation Act of 1966, the National Register is part of a national program to coordinate and support public and private efforts to identify, evaluate, and protect historic and archeological resources. Properties list-ed in the Register include districts, sites, buildings, structures, and objects that are significant in U. S. history, architecture, archeology, engineering, and culture. The National Register is administered by the National Park Service, which is part of the U. S. Department of the Interior. The National Register accepts applications for buildings, which meet certain specific historic requirements.

Owners of properties listed in the National Register may be eligible for a 20% investment tax credit for the certified rehabilitation of income-producing certified historic structures such as commercial, industrial, or rental residential buildings. This credit can be combined with a straight-line depreciation period of 27.5 years for residential property and 31.5 years for nonresidential property for the depreciable basis of the rehabilitated building reduced by the amount of the tax credit claimed. Federal tax deductions are also available for charitable contributions for conservation purposes of partial interests in historically important land areas or structures.