Before we study long-span construction, let us define a very important concept, which we have missed, earlier and i.e. Building.
A Building means a structure constructed with any materials what so ever for any purpose, whether used for human habitation or not & includes - foundation, plinth, walls, floors, roof, chimney, plumbing & building services, fixed platform, verandahs, balconies, comices, projections: part of a building or any thing affixed thereto: any wall enclosing or intended to enclose land or space, signs & outdoor display structures, tanks constructed for storage of chemicals or chemicals in liquid form, & all types including assembly building, business building, detached building, educational building or hazardous building except for tents, shamiyanas & tarpaulin shelters erected for temporary purposes for ceremonial occasions, with the permission of the concern officer or any other official empowered by him in this behalf.
Now lets start with Long-span construction. When is a span a long span? One answer is: when, as a consequence of the size of the span, technical considerations are placed so high on the list of architectural priorities that they significantly affect the aesthetic treatment of the building.
Structures like aircraft hangers, coliseums, or atriums, that require greater open areas between columnar supports than standard wood or steel structural members can span, are built with long span construction technology. Many designs have been used successfully depending on the area to be spanned; the anticipated roof loads, occupancy use, etc. also in long-span construction the outside walls solely support the entire roof structure. Inside walls are usually false or non-load bearing walls. Long-span buildings create unobstructed, column-free spaces greater than 30 meters (100 feet) for a variety of functions. These include activities where visibility is important for large audiences (auditoriums and covered stadiums), where flexibility is important (exhibition halls and certain types of manufacturing facility), and where large movable objects are housed.
The technical problem posed by the long span is that of maintaining a reasonable balance between the load carried and the self-weight of the structure. The forms of longest-span structures are therefore those of the most efficient structure types. In the pre-industrial age, the structural form that was used for the widest spans was the masonry vault or dome.
The development of reinforced concrete in the late 19th century allowed the extension of the maximum span possible with the compressive form-active type of structure.
Reinforced concrete has a number of advantages over masonry, the principal one being its capability to resist tension as well as compression and its consequent ability to resist bending.
Also Long-span structures in steel developed more slowly than the high-rise in the years from 1895 to 1945.