The Theory of Special Legislation
In Appeal of Apgar from Decision of Bd. of Comm'rs of Manheim Twp., 661 A.2d 445, 448 (Pa. Cmwlth. 1995), the Court explained:
In deciding the validity of a zoning ordinance, the courts have consistently limited the application of the theory of special legislation to situations where amendatory zoning ordinances were adopted to deprive the applicant of vested interests in permits issued before the amendment or to prevent a permitted use proposed in the pending application ....
Thus, an amendatory zoning ordinance constitutes special legislation only where it is enacted to prevent a lawful use of land permitted under the existing ordinance. Id.
In Apgar, the Court rejected a special legislation claim based on the fact that the ordinance amendment at issue in that case had no confiscatory application and was not enacted to prevent any lawful use of land.