In structures making use of the short shell, the principle structural element is the stiffener, usually a reinforced concrete arch, although steel arches or trusses have been used. The short shell serves only a minor role, therefore, the emphasis in this chapter then will be on the arch shape. Many structures built with short shells, such a large hangars and auditoriums, could have been built with little more dead load by using a ribbed slab or other lightweight concrete framing system rather than the shell. The architecture of short shells, therefor, must be based on the exploitation of the shape of the arch rather than on the shell itself.