A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Abacus - The flat stone slab underneath the entablature that forms the top of the capital of a classical column supporting a beam. Acanthus - A Stylized leaf motif, one of the primary decorative elements of classical architecture. With its origins in Greece, it was adopted by Romans and transmitted into the general classical tradition. Acropolis - The symbolic center of a Greek city-state, bringing together its most important sacred and civic buildings in one urban space, as in Athens where the Parthenon forms the heart of the Athenian acropolis. Adobe - Mud bricks reinforced with straw. Used particularly in Latin America and southwestern USA, adobe produces a distinctive architectural style based on organic forms, a smooth finish, and a minimum of window openings. Aedicule - A term now applied to the frames surrounding a classical doorway or window flanked by a pair of columns and topped by a pediment, but which has its origins in the architectural treatment of the shrines of the classical period. A-Frame - A roof shape with a very steep pitch forming a gable or "A" shape. Agora - The public open space that formed the heart of ancient Greek cities and it's the origin of most western conceptions of public, or civic, space as center of for social interaction for ceremony and democratic life on a pedestrian scale. Air Space - A space provided in exterior wall construction to prevent passage of moisture and allow the wall to dry out. Aisle - The portion of a church flanking the nave and seperated from it by a row of columns or piers. In general, the space between the arcade and an outer wall. Alcazar - A building type that is a legacy of the Moorish occupation of Spain, a fortified palace found mainly in south of the country, particularly Seville and Granda. Align - The faces of objects that are in line with each other, or when their center-lines lie on the same axis. Aluminum Siding - Lightweight material that is often painted rather than left in its natural color. Alterpiece - A panel, painted or sculptured, situated above and behind an altar. Amphitheater - The circular structure characterized by rising tiers of stone seats contained within an arched stone outer wall that was used by Romans for circus performances and gladiatorial contest. Ambulatory - A covered walkway, outdoors (as in a cloister) or indoors: especailly the passwage around the apse and the choir (quire) of a church. Anchor Bolt - A bolt or threaded rod used to secure the sill to the foundation wall. Angle Iron - Provides supporting lintels for openings in masonry wall construction. Apron - The horizontal member directly beneath the stool or inside sill of a window. Apse - A semicircular and usually vaulted projection from a rectangular structure. Origins of the word are classical, but it is most commonly used to describe an element of a Gothic church. A recess, usually singular and semi-circular, at the east end of a Christian church. Arcade - A series of arches supported by piers or columns. Arcading - An uninterruped series of arcades. Arch - A curved structure used as a support over an open space, as in a doorway. A Semicircular opening in a wall, or a freestanding structure dependent for its structural stability on the horizontal load threatening to push it apart. Usually made from cut stone blocks forming interlocking wedges.. Architrave -ls Originally a simple, flat, structural lintel spanning an opening in a wall, it is th elowest part of the classical entablature. Subsequently a term used to describe any molded door or window frame. Archivolt - Onee of a series of concentric moldings on a Romanesque or a Gothic arch. Area wall - The retaining wall surrounding a basement window which is below ground level. Areaway - The excavated area between the Area wall and the basement window. Art Nouveau - A movement that embraced architecture, design, and visual arts throughout Europe. It was fashionable between 1890 and 1910, and particularly strong in France, Belgium, Germany, and Austria. In Britain, Charles Rennie Mackintosh was an important exponent: in Spain, Antonio Gaudi was the leading figure. It attempted to find what was sometimes called a modern style, using natural, organic forms and decorative motifs rather than historically derived elements. Marked by ornate use of undulation, such as waves, flames, floweer stalks and flowing hair. Arts and Craft - Galvanized by William Morris's disgust at what he perceived as the dehumanizing tendencies of mass production and the factory system, a group os architects and designers attempted to revive the traditions of simple handicraft techniques in 19th century Britain. In architecture they looked at the unselfconscious vernacular tradition of barns, mills, and cottages as an inspiration and at the aesthetics of the medieval period. Known as the Arts and Crafts movement, this design tendency spread across much of Europe to America and Australia. Art deco - A popular design of the 1920s and "30s characterized by bold outlines, geometric and zigzag forms. Asbestos - A fibrous, incombustible material once used in building construction. No longer allowed due to health risk. Asbestos Shingles - A shingling material made up of a nonconducting, fireproof mineral used in roofing and siding. No longer allowed due to health risk. Ash dump - A small opening located in the hearth of a fireplace having a cast iron cover, used to dump the ashes down into a cavity below the fire box. Ashlar - The practice of laying stone in smooth cut - or dressed - blocks in regular courses, seperated by only the thinnest of joints. Originated by the ancient Egyptians and adopted as an important element of classical architecture. Ashlar Masonry - Masonry construction using a square stone. Asphalt Shingle - A roofing material made of a brown or black tar like substance mixed with sand or gravel. Atrium - In the Roman period this was the inner courtyard of a house, left open to the sky, and generally built by the affluent urbam classes. In the 20th century the word has been adopted to describe dramatic enclosed glass-roofed indoor spaces associated with high-rise hotels and office buildings that are treated as substitutes for the public realm. Aumbry - A recess to hold sacred vessels, often found in castle chapels. Awning Window - A window hinged along the top edge. Axis (pl. axes) - The centerline of openings or objects that align in a row along an imaginary line. A primary element in architectural composition, around which it is possible to create a sense of symmetry both in plan and in the elevation of a building. Axonometric - A drawing technique devised to represent three dimensional objects on flat paper. Verticals are drawn to scale, but diagonal dimensions are distorted.