Stacks and Layout A row of shelving units, single-faced or double-faced, makes up a range. Stacks consist of ranges of shelves and the aisles that give access to them. Aisle nomenclature specifies their locations within the shelving layout; side aisles run parallel to the stacks while cross aisles run perpendicular to the side aisles, providing breaks in the side aisles. End aisles are at the end of a group of ranges and may serve single-faced sections against a wall. Main aisles, also perpendicular to side aisles, are a part of major access routes. As means of egress the characteristics of the aisle – width, height and length – affect the occupant’s health, safety and welfare and must comply with building, safety and accessibility regulations. Optimal shelving layouts use ranges of six to seven double-faced shelving units, although practice permits longer ranges. The length of such a range maximizes the linear continuity of shelving while remaining within comfortable lengths of travel.
The Jacob-und-Wilhelm-Zentrum in Berlin (bottom) uses four-post case style shelving units, while the Seattle Central Library (top) has a cantilever shelving system. These are the two systems predominately used in library collections.
While book capacity is important, human comfort is of equal importance in shelving layouts. Repetitive shelving ranges are, in fact, densely positioned walls and, depen ding on the aisle width and shelving height used, they impact the p sychological perception of the space. In heavily trafficked urban libraries, for example, a shelving aisle of minimum width could be perceived as less inviting than a wider one. Similarly, shelving ranges of more than six shelves in length (each shelf at 1.2 m) comply with travel distances but may be perceived as oppressive or even threate ning in some situations. Shelving heights (or numbers of shelves per unit height) are determined as a compromise of volume capacity and the atmosphere created by such height. Seven-shelf high shelves are most efficient in terms of book storage, but their height renders the top shelves inaccessible for universal reach. Allowing also for the advantage of organizing oversized volumes within the running order of the collection (requiring greater spacing of the shelves), shelving height in publicly accessible libraries is typically limited to six shelves or even five shelves. While maximum shelving capacity is an issue of economics, the design parameters of aisle widths and shelving lengths and heights are determinants of the atmosphere of a stack area.
Typical shelving layout
103