Lancaster, Strasburg, Columbia and Lititz have established historic districts under state guidelines. These districts also are listed on the National Register of Historic Places. They encompass thousands of residences and other structures.
Historical Architectural Review Boards, or HARBs, sit in judgment on proposals for exterior modifications, including demolition, in all of the districts except Lititz, which has a slightly different system. Alterations include removing a porch or replacing wood windows with vinyl.
The point of monitoring these changes is to preserve the integrity of the historic districts. Methods of meeting that objective still draw occasional controversy decades after the historic districts were established.