staircase.
1. Structure enclosing a stair, also called the staircase-shell, or well.

2. Stair with balustrade.

3. Whole stair with supporting framework, balusters, etc.

Grand staircases with architectural pretensions are of considerable antiquity and were known in ancient Crete and Mesopotamia. In Classical Antiquity, curiously enough, staircases were not often exploited as architectural elements, and it was only with the Renaissance that staircases began to be developed architecturally, notably with Bramante's staircase at the Belvedere Court, Vatican, and the Imperial staircase at the Escorial, near Madrid, by Juan Bautista de Toledo and de Herrera (1563–84). Palladio seems to have been responsible for the flying or geometrical stair, much used in C18. During the Baroque period staircase-design progressed to such masterpieces as the Treppenhaus in the Residenz (Seat of the Court) at Würzburg by Neumann. Staircases were often expressed as powerful architectural elements, notably by Gropius, Mendelsohn, and others in C20.

Bibliography

B&M (1989);
Cd'ÉSdlR (1985);
C&G (1985);
Gambardello (1993);
Pevsner (ed.) (1960);
Templer (1992)

stair·case / ˈste(ə)rˌkās/ • n. a set of stairs and its surrounding walls or structure.