(1) Every wall supported by another all or a structural member shall be supported on a foundation complying with the provisions of Chapter 4, except where the local authority permits the construction of a wall on solid rock after having satisfied itself that the safety of the building will not be endangered by the omission of a foundation.

(2) Except as provided in section 21, no wall shall be allowed to carry a wall thicker than itself, and where, in a building, walls are interrupted by floor-slabs, every wall in each storey shall be located vertically over the wall below, unless full provision is made in the design of such building to support a wall in another position.

(3) Lateral stability to a building as a whole shall be provided by cross-walls or by other means which are to the satisfaction of the local authority.

(4) Empirically constructed walls other than wing-walls, free standing walls and retaining-wall shall have adequate lateral supports at each end.

(5) Empirically constructed external walls shall be either moderately or fully restrained at the top in each storey of a building.

(6) Empirically constructed gable-walls shall be securely anchored to the roof along the top of the gable, and, where necessary, in the opinion of the local authority, provision shall be made at such anchorage to accommodate movement of the roof due to expansion or contraction of the roof.