The brick diaphragm wall is a wide-cavity wall with the two leaves bonded together not by the normal cavity ties but by cross-ribs of brickwork. The leaves and cross-ribs, acting integrally, form a series of connected box or I-sections having a high section modulus and radius of gyration. This gives the wall a much greater resistance to lateral and vertical loading than the normal cavity wall. The technique enables diaphragm walls to be used for tall single-storey structures where experience and investigation have shown them to be faster, simpler, and cheaper to construct than the
traditional steel frame and cladding. The paper discusses the development of the idea, its applications, the design philosophy, and future developments.