Dog-leg (stairs)

A dog-leg is a configuration of stairs between two floors of a building, often a domestic building, in which a flight of stairs ascends to a quarter-landing before turning at a right angle and continuing upwards. 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 quarter-landing, which spans the adjoining flank walls. It is called a "quarter" because it is constructed at a 90 degree angle, which is a quarter of a 360-degree circle.

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 more 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.

An open-well or straight staircase has some advantages over dog-leg stairs, including that the handrail can be continuous, which is helpful for elderly or disabled people.

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