Aluminum or vinyl siding is not a recommended treatment for historic buildings that predate the introduction of such siding because it may conceal historic features and/or may damage underlying historic material due to moisture retention. The national and state registers do not definitively exclude vinyl-sided buildings from consideration. A property must, however, retain physical integrity sufficient to convey its historic significance in order to be listed in the Registers. Non-historic and/or unsympathetic alterations tend to erode physical integrity. The cumulative effect of alterations may make a property not eligible for the Registers. Property owners are encouraged to review DHR’s evaluation and nomination process when contemplating whether they want to nominate their property for individual listing in the Registers.