Dog-leg is a term used to describe a configuration of stairs between two floors of a building, often a domestic building, in which there are two short flights running parallel to each other, joined by a half-landing to enable the 180 degree turn. The flights do not have to be equal, and frequently are not.
Structurally the flights of a dog-leg stair are usually supported by the half-landing, which spans the adjoining flank walls.
From the design point of view the main advantages of a dog-leg stair are:
- To allow an arrangement that occupies a shorter, though wider, floor area than a straight flight, and so is more compact. Even though the landings consume total floor space, there is no large single dimension
- The upper floor is not directly visible from the bottom of the stairs, thereby providing more privacy