Pennsylvania Statutes Title 53 P.S. Municipal and Quasi-Municipal Corporations § 15063. Windows;  corridors

Every room in every such tenement house shall have at least one window opening upon a street, or upon the open space provided for in the second section of this act.  1  And the distance from every window in every such tenement house to the wall or party line opposite to it shall be at least eight feet.  The halls on each floor of every such tenement house shall have a window or windows opening either upon a street or upon the open space provided for in the second section of this act,  1 and shall have no room or other obstruction at the end, unless sufficient light and ventilation is otherwise provided for said halls in a manner approved by the chief of the bureau of building inspection.  But whenever in the judgment of the chief of the bureau of building inspection it shall be possible to construct such tenement house without corridors connecting the entrance of several tenements or suites of rooms, the chief of the bureau of building inspection may require that such tenement house be so constructed that it shall contain no such corridors.