See also: Span (homonymy)

A span , in the field of the Architecture, is an opening delimited by two vertical supports constituting the principal fulcrums or the showpieces of a construction (pillars, columns, farms, beams etc). The span can also be the part of a Nef, a vessel, a roof, a Plancher of building ranging between two principal fulcrums or two arcade S or two firm or two beams which are done opposite. More generally, the word span indicates in architecture a division of a room, i.e. a covered space of polygonal plan whose supports are located at the tops.

The various following types of spans are met:

• the rhythmic span is a grouping formed of a principal bay, generally covered with a arc in full-clotheshanger, framed each side by two superimposed, real or pretended secondary bays (niches, tables, etc), one under the level of the Imposte of principal bay, the other above.

• the span of balusters is a row of Balustre S between two columns or pedestal.

• the span of grid is a row of bars between two pillars or two Pilastre S.

• the span of gallery is a fraction of gallery giving on the nave.

• In a Frame, the span is the part of a ceiling ranging between two main beams or the wall and main beam.

• In the Public works, the span is the part of a Pont ranging between two successive supports.

• In a Library, a span is a whole of superimposed shelves, ranging between two vertical supports.

• the span can be the zone of a room occupied by lines of seats or benches directed in the same direction (towards a furnace bridge, a scene, a estrade…), the space occupied by lines of tables, benches, racks, etc, or space circulation between these lines; or by Métonymie, the whole of people who occupy a span.