The Pennsylvania Supreme Court has held that the Rent Withholding Act is not an unconstitutional delegation of legislative authority, despite the fact that it leaves to the Department of Licenses and Inspections the task of applying the concepts of "fit and unfit for human habitation"; nor does it act as an unconstitutional taking of landlords' property without due process of law.
DePaul v. Kaufman, 441 Pa. 386, 272 A.2d 500 (1971).
Mark L. Glosser,
Constitutional Law - Rent Withholding Act,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol10/iss1/14