Staircase

A stairwell or stair room is a room in a building where a stair is located, and is used to connect walkways between floors so that one can move in height.^[1] Collectively, a set of stairs and a stairwell is referred to as a staircase or stairway. In buildings with several housing units, a stairway can be a necessary common area for getting to and from apartments.

Staircases provide vertical access to connected floors in a multi-story building, and are a functional part of it. Stairwells are often used to place several stairs one above the other to save vertical space.^[2] The entrance to elevators is often located in the stairwell. Sometimes the stairwell goes around the lift shaft, other times it is placed next to it.

An exterior stairway is a stair in a separate structure attached to the rest of the building body,^[3] and can either be enclosed or exposed to the elements. Such temporary exposed stairways are sometimes used in conjunction with scaffolding on construction sites, or permanently as an emergency exit.