53 Pa. Stat. § 14213
Before such recommendation shall be made by the said boards, they shall give due notice to the owner or owners of the properties to be affected, that such recommendation is contemplated, and that the parties will be heard in relation thereto, and when such recommendation as aforesaid, after such hearing shall have been made to councils, and an ordinance passed in pursuance thereto, the owner or owners of the properties to be affected shall have notice, in writing, given to him or them, by the department of public works, of the fact that such properties will have to be removed, altered or modified, and of all the particulars of the treatment to be accorded to the same, as embraced in the said ordinance, and should the owner or owners, after the receipt of said notice, fail for the period of six months thereafter, to commence and prosecute the work of removal or reconstruction, as prescribed in the said notice, said cities shall have power to condemn and appropriate said properties and improvements, and riparian rights, and the fee simple thereto shall become vested in the said cities for the purposes as recited in the first section of this act: Provided, That the owner or owners of said properties and rights so purchased or taken shall receive compensation therefor, in the mode provided for ascertaining damages, by reason of change of grade of streets in cities of the first class, excepting that there shall be no assessment of benefits upon properties in the immediate vicinity.
53 P.S. § 14213