53 Pa. Stat. § 25006
Every tenement house basement room, hereafter constructed, for living purposes, and every basement room in already existing buildings, which shall be converted into a living room, shall have the ceiling at least eight feet six inches in every part from the floor, and shall be at least one-half its height above the level of the street or ground outside of or adjoining the same; where the grade of the street or ground adjacent to a tenement house varies, the mean, or average, grade shall be taken to conform to the provisions of this act. Such room shall have a window or windows, opening upon the street or upon a yard or court. The total area of the windows in such room shall be at least one-eighth of the floor area of the room, and one-half of the sash shall be made to open the full width, and the top of each window shall be within six inches of the ceiling. There shall be appurtenant to every such room or apartment a water closet, conforming in design, materials and construction to the building and health regulations of cities of the second class.
53 P.S. § 25006