In architecture, a pilaster is both a load-bearing section of thickened wall or column integrated into a wall, and a purely decorative element in classical architecture which gives the appearance of a supporting column and articulates an extent of wall. As an ornament it consists of a flat surface raised from the main wall surface, usually treated as though it were a column, with a capital at the top, plinth (base) at the bottom, and the various other column elements. In contrast to a Classical pilaster, an engaged column or buttress can support the structure of a wall and roof above.
In human anatomy, a pilaster is a ridge that extends vertically across the femur, which is unique to modern humans. Its structural function is unclear.[1]
Definition
A pilaster is foremost a load-bearing architectural element used widely throughout the world and its history where a structural load is carried by a thickened section of wall or column integrated into a wall.
It is also a purely ornamental element used in Classical architecture. As such it may be defined as a flattened column which has lost its three-dimensional and tactile value.".[2]
In Classical architecture
In discussing Leon Battista Alberti's use of pilasters, which Alberti reintroduced into wall-architecture, Rudolf Wittkower wrote: "The pilaster is the logical transformation of the column for the decoration of a wall.
A pilaster appears with a capital.[3] and entablature, also in "low-relief" or flattened against the wall. Generally, a pilaster often repeats all parts and proportions of an order column; however, unlike it, a pilaster is usually devoid of entasis.
Pilasters often appear on the sides of a door frame or window opening on the facade of a building, and are sometimes paired with columns or pillars set directly in front of them at some distance away from the wall, which support a roof structure above, such as a portico. These vertical elements can also be used to support a recessed archivolt around a doorway. The pilaster can be replaced by ornamental brackets supporting the entablature or a balcony over a doorway.
When a pilaster appears at the corner intersection of two walls it is known as a canton.[4]
As with a column, a pilaster can have a plain or fluted surface to its profile and can be represented in the mode of numerous architectural styles. During the Renaissance and Baroque architects used a range of pilaster forms.[5] In the giant order pilasters appear as two storeys tall, linking floors in a single unit.
^Wittkower, Rudolf (1940). "Alberti's Approach to Antiquity in Architecture". Journal of the Warburg and Courtauld Institutes. 4 (1/2: Oct., 1940 - Jan., 1941). London: Warburg Institute: 3. doi:10.2307/750120. JSTOR750120. S2CID195049595.
^A useful phrase to identify a section of pilaster without a capital, with only its fluting to identify its relation to a column, is "pilaster strip".
^Ching, Francis D. K. (1995). A Visual Dictionary of Architecture. Van Nostrand Reinhold Company. ISBN0-442-02462-2, p. 266.