53 Pa. Stat. § 14966
In every rooming-house there shall be at least one water-closet, in a separate compartment, for every four rooms or major fractional part thereof, approached by an entrance independent of any living room. In each two-family house or tenement there shall be at least one water-closet, contained in a separate compartment, for each family occupying the premises; except that, where there are apartments of one or two rooms, there shall be at least one water-closet for each three families, located in a separate compartment on the same floor with the apartments it is to serve, if feasible; otherwise, it shall be in a place easily accessible to such apartments. Such water-closet shall be approached by at least one entrance independent of a living room. At least one water-closet, for each other apartment in such buildings, shall have at least one entrance by separate hall or passageway, independent of a room used for sleeping purposes; except that, where such apartment consists of a kitchen, a bath-room and not more than two living-rooms, and is occupied by not more than one family, said entrance may be direct from a living-room. No water-closet shall be maintained in the cellar or basement of any building, without a permit from the Bureau or Board of Health; but under no circumstances shall the general water-closet accommodations of a rooming-house or tenement be permitted in a cellar or basement.
53 P.S. § 14966