The building is in the form of a simple cube with subsidiary elements inserted into or projecting from it. This, together with its choice of materials and construction, creates an attractive, flexible, high-precision environment suited to its purpose. The basement is reinforced concrete, and the ground and upper storeys have an exposed steel skeleton. The stairs on the west side are the emergency exit from the open sales floor and the basement. Strips of flat stainless steel are inset into the construction joints in the fair-faced concrete. The monolithic steps and landings are supported via projecting bars in a solid wall slab rising from the basement.