The main architectural challenge in the design of the shop was the limited floor to ceiling height of the car park. A series of domes and vaults were created to provide the illusion of height. It allowed specific areas to be defined within the shop whilst keeping the space as open as possible for circulation and the display of merchandise. The overall design of the shop, together with the display cabinets and furniture, was carried out by John Simpson Architects. The shop, for the Royal Collection Enterprises, sells a variety of merchandise, including books, jewellery, porcelain and posters.