spandrel

A triangular space on the wall of a building, defined by the curve of an arch, a vertical line drawn up from the side of the arch, and a horizontal line through its apex. Particularly in 20th-c architecture, it refers to an infill panel below a window, often of a different material to the rest of the wall.

A spandrel (less often spandril or splaundrel) is the space between two arches or between an arch and a rectangular enclosure.

There are four or five accepted and cognate meanings of spandrel in architectural and art history, mostly relating to the space between a curved figure and a rectangular boundary - such as the space between the curve of an arch and a rectilinear bounding moulding, or the wallspace bounded by adjacent arches in an arcade and the stringcourse or moulding above them, or the space between the central medallion of a carpet and its rectangular corners, or the space between the circular face of a clock and the corners of the square revealed by its hood.

In a building with more than one floor the term spandrel is also used to indicate the space between the top of the window in one story and the sill of the window in the story above.

Because arches are commonly used in bridge construction, spandrels may also appear in those structures. Historically, most arch spans were solid-spandrel, meaning that the areas between arches were completely filled in — usually with stone — until the advent of steel and reinforced concrete in the 19th and 20th centuries. Open-spandrel bridges later became fairly common, where thin ribs were used to connect the upper deck to the bridge arches, resulting in a significant savings in material, weight, and therefore cost.

Spandrels can also occur in the construction of domes, and are typical in grand architecture from the medieaval period onwards.

See also: Cathedral architecture

This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.