53 Pa. Stat. § 22774
The city shall not accept, lay out, open, improve, grade, pave, curb, or light any street, or lay or permit water mains or sewers or connections to be laid in any street, unless such street shall have been accepted or opened as, or shall otherwise have received the legal status of, a public street prior to said action or unless such street corresponds with a street shown on the official master plan, or with a street on a subdivision plat approved by the planning commission, or with a street on a street plat or official map made by and officially adopted by the commission. Council may, however, accept any street not shown on, or not corresponding with a street on, the official master plan or on an approved subdivision plat or an official street plat or the official map, provided the ordinance or other measure accepting such street be first submitted to the city planning commission for its approval and, if approved by the commission, be enacted or passed by not less than a majority vote of the entire membership of council, or, if disapproved by the commission, be enacted or passed by not less than a two-thirds vote of the entire membership of council. A street approved by the planning commission upon submission by council, or accepted by a two-thirds vote after disapproval by the planning commission, shall thereupon have the status of an approved street, and part of the official street map, as fully as though it had been originally shown on the official master plan or on a subdivision plat approved or plotted by the planning commission or on an official street plan.
53 P.S. § 22774