141. A building may form an integral part of a building covering the surface opening of an underground mine provided that:(1) (paragraph revoked);
(2) each part of the integrated building is of non-combustible construction and each part of the building covering the surface opening of the underground mine is constructed with non-combustible materials;
(3) the part of the building covering the surface opening of the underground mine is separated from the rest of the building by a wall having a fire resistance of at least one hour and is constructed with non-combustible materials.