53 Pa. Stat. § 14611
Whenever in any city of the first class any building or premises is being maintained in a condition which is found to be hazardous, structurally unsound, dangerous or unfit for human habitation and in violation of any law or ordinance, such building or premises may be declared to be a nuisance by the Department of Licenses and Inspections, and a notice of such finding and declaration shall be served upon the registered owner of the building or premises directing the abatement of the nuisance. The notice shall reasonably specify such repairs or such other measures, including demolition, as may be necessary to abate the nuisance and shall require their completion within a reasonable time not less than thirty days from the date of service of the notice.
53 P.S. § 14611