Architectural Terms – Drafting How To's

This glossary of architectural and building terms serves as a quick reference for anyone involved in construction, design, or simply curious about the language of architecture. Whether you’re a student, builder, or homeowner exploring renovations, these definitions provide clarity on key terms and concepts.

Abacus. The topmost division of the capital of a column.
Abutment of an Arch. The mass of masonry which resists the thrust of the arch. That against which the ends of the arch rest.
Aisle. The side portion of a building, separated from the center portion usually by columns or piers.
Angle Iron. A structural iron shape whose cross section is in the form of a letter L.
Annulets. The band of small moldings at the bottom of the Echinus of the Greek Doric capital.
Antae. A pilaster attached to a wall.
Apron. The finished board placed immediately below a window stool.
Arcade. A series of arches.
Architrave of a Door or Window. The molded finish around the opening.
Architrave of an Entablature. The lower division of the entablature.
Arris. The edge formed by the intersecting of two surfaces.
Ashlar. The outside cut stone facing of a wall.
Astragal. A small moulding of circular section. See column capital of Plate 63. Also the moulding separating two doors, etc.
Attic. That part of a classic structure that occurs above the cornice level. Also the space immediately under the roof of a house.
Back-band. The outside member of a window or door casing.
Back Hearth. That part of the hearth inside the fireplace.
Backing. The inner portion of a wall.
Balcony. A platform projecting from the building wall.
Base. The lower member of a column or a building.
Base Board. The finishing board covering the plaster wall where it meets the floor.
Batten. A strip of board for use in fastening other boards together.
Batter. The slope of the face of a wall that is not plumb.
Batter Boards. Boards set up at the corners of a proposed building from which are stretched the lines marking off the walls, etc.
Bay. A comparatively small projecting portion of a building. Also one division of an arcade or the space between two columns.
Beam. A large horizontal structural member supporting floors, etc.
Bond. The connection between the bricks or stones of a masonry wall formed by overlapping the pieces.
Box Frame. A window frame containing boxes for the sash weights.
Bridging. A cross-bracing built between joist and studs to add stiffness to floors and walls.
Building Line.—The line of the outside face of a building wall. Also the line on a lot beyond which the law forbids that a building be erected.
Building Paper. A heavy, more or less waterproof paper for use in insulating the walls, floors and roofs of buildings.
Buttress. An enlargement or projection of a wall to resist the thrust of an arch, etc.
Butts. Hinges designed to be screwed to the edge or butt of a door or window and the inside of the frame.
Camber. The convex curve of the edge of a joist or Other member.
Carriage. The framing timber which is the direct support of the stair steps.
Casement. A window whose frame is hinged at the side to swing out or in.
Catch Basin.—A simple cast iron or cement receptacle into which the water from a roof, area way, etc., will drain. It is connected with a sewer or tile drain.
Caulicoli. The stalks which spring from the second row of leaves of the Corinthian capital and extend up to form the volutes under the corners of the abacus.
Centering. The false work upon which is built masonry arches, concrete slabs, etc. In concrete work the centering is also known as the forms.
Channel. A structural steel shape.
Client. The employer of the architect. The owner who entrusts the carrying out of his building project to the designer and engineer.
Coffer. A deeply recessed panel, usually in a ceiling or dome.
Collar Beam. A horizontal timber tying two opposite rafters together at a more or less central point of the rafters.
Colonnade. A continuous series of columns.
Console. A supporting bracket usually ornamented by a reverse scroll.
Coped Joint. A joint between molded pieces in which a portion of one member is cut out to receive the molded part of the other member.
Corbel. A bracket formed on a wall by building out successive courses of masonry.
Corner Bead. A metal bead to be built into plaster corners to prevent accidental breaking off of the plaster.
Cornice. The part of a roof which projects beyond the wall. The upper main division of a classic entablature.
Corona. The plane center member of a classic cornice.
Court. An open space surrounded partly or entirely by a building.
Cresting. The ornamental finish of a roof ridge or the top of a wall.
Cupola. A small cylindrical or polygonal structure on the top of a dome.
Curtain Wall. A thin wall supported independent of the wall below, every one or two stories, by the structural steel or concrete frame of the building.
Cyma. One form of a moulding.
Cymatium. The name given to a cyma moulding when it is used as a crowning moulding.
Dentils. Rectangular supporting blocks beneath the cornice of an entablature.
Diaper. An over-all decorative pattern.
Die. The plane center member of a pedestal. When continuous it is called a Podium.
Dormer. A structure projecting from a sloping roof, usually to accommodate a window.
Drain. A means of carrying off waste water. See also House Drain.
Drip Mould. A moulding designed to prevent rain water from running down the face of a wall; used also to protect the bottom of doors, windows, etc., from leakage.
Echinus. The half-round molded part of a column capital directly below the abacus.
Elevations. Drawings of the walls of a building, usually made as though the observer were looking straight at the wall.
Escutcheon Plate. The protective metal plate at a keyhole. Sometimes merely an ornamental plate around an opening.
Extrados. The name applied to the upper or outside curving line of an arch.
Face Brick. Usually a special brick used for “facing” a wall.
Fenestration. The distribution or arrangement of windows in a wall.
Finial. The ornamental termination of a pinnacle, consisting of leaf forms, etc.
Flange. The upper and lower cross parts of a steel I beam or channel. A projecting rib.
Flashing. The sheet metal work to prevent leakage over windows, doors, etc., and around chimneys and at other roof details.
Floor Plan. The horizontal section through a building showing size and location of rooms, also doors, windows, etc., in the walls.
Footing. The spread portion at the bottom of a basement / foundation wall or column to prevent settlement.
Freestone. A soft, easily worked variety of sandstone.
Fresco. Painting on fresh plaster before it has dried. Commonly, though incorrectly, used for any painting on plaster.
Frieze. That part of a classic entablature between the cornice and the architrave.
Furring. The leveling up or building out of a part of a wall or ceiling by wood strips, etc.
Gable. The triangular portion of an end wall formed by the sloping roof.
Gable Roof. One sloping up from two walls only.
Gain. The mortise or notch cut out of a timber to receive the end of a beam.
Gambrel Roof. A roof having two different slopes.
Gargoyle. A projecting ornamental water spout to throw the roof water clear of the walls below.
Girder. A large horizontal structural member, usually heavier than a beam and used to support the ends of joists and beams, or to carry walls over openings.
Girt. The heavy horizontal timber carrying the second floor joist in a braced frame building.
Grade. The level of the ground around a building.
Grille. A protective metal screen, sometimes highly ornamented.
Groined Vaulting. A ceiling formed by several intersecting cylindrical vaults.
Grout. A thin mortar for filling up spaces difficult of access or where the heavier mortar would not penetrate.
Guttae. The drops used for enriching the Greek Doric Order and the Mutular Doric. They are cylindrical in the first and conical in the second example.
Gutter. A trough or depression for carrying off water.
Halving. A method of splicing the ends of two timbers by cutting half of each away and overlapping these parts. The joint is thus the same size as the timbers.
Hanging Stile. The vertical part of a door or casement window to which the hinge is fastened.
Hatching. The shading of an imaginary cut surface by a series of parallel lines.
Head Room. The vertical clearance on a stairway or in a room.
Hearth. The vitreous portion of a floor in front of a fireplace.
Heel. The end of a rafter that rests on the wall plate.
Herring-bone. The name given to masonry work when laid up in a zig-zag pattern. It is usually found in brick work.
Hip-roof. One sloping up from all walls of the building.
Hood. The small roof over a doorway, supported by brackets or consoles.
House Drain. The horizontal piping beneath the basement floor of a building, which carries off the discharge from all soil and waste lines to a point outside the building.
House Sewer. The drainage pipe connecting with the house drain at a point about 5 feet outside the building and leading to the sewer or septic tank.
Housing. The part cut out of one member so as to receive another.
Hypotrachelium. That part of the Greek Doric capital that occurs directly beneath the annulets of the echinus.
Impost. The top member of a wall, pier, etc., from which springs an arch. It may be the capital of a pier or just a moulding on a wall.
Incise. To cut into, as letters incised or carved into stone.
Intercolumniation. The clear space between columns.
Intrados. The name applied to the lower or inside curving line of an arch.
Jamb. The inside vertical face of a door or window frame.
Joist. The framing timbers which are the direct support of a floor.
Key-stone. The center top stone of an arch.
Label. The ornamental drip moulding over an arch.
Lancet Window. A high narrow window pointed like a lance at the top.
Lantern. The small structure projecting above a dome or roof for light or ventilation.
Lean-to. A small building against the side of another and having a roof sloping away from the larger structure.
Lintel. The horizontal structural member supporting the wall over an opening.
Lobby. An entrance hall or waiting room.
Loggia. A hall within a building but open on one side, this side being usually supported by a colonnade.
Lookout. A short timber for supporting the projecting cornice.
Louver. A ventilating window covered by sloping slats to exclude rain.
Mansard Roof. A hipped roof having two slopes similar to the gambrel roof.
Mantel. The shelf and other ornamental work around a fireplace.
Marquetry. An ornamental surface built up of small pieces of various hard woods to form a pattern. Inlaid work.
Medallion. A round or elliptical raised surface, usually for ornamental purposes.
Meeting Rail. The horizontal rails of window frames that fit together when the window is closed.
Metope. That part of the frieze between the triglyphs of the Doric Order.
Mezzanine. A low secondary story contained in a high story.
Mill-work. The finished wood work, machined and partly assembled at the mill.
Minaret. A Turkish turret with balconies.
Miter. A beveled surface cut on the ends of moldings, etc., that they may member at points where they change direction.
Modillion. An ornamental bracket supporting a cornice.
Module. An accepted division for measuring proportions of the Orders of Architecture. It is taken as one half of the base diameter of the column.
Mullion. The large vertical division of a window opening. In grouped windows it is the member that separates the sash of each unit.
Muntins. The small members that divide the glass in a window frame.
Mutules. The rectangular blocks supporting the cornice of the Mutular Doric Order.
Narthex. A hall or lobby at the entrance of a church.
Nave. The main or central portion of a church auditorium.
Necking. The middle member of a simple column capital.
Newel. The post where the handrail of a stair starts or changes direction.
Niche. A recess in a wall; often to accommodate a piece of statuary.
Ogee. A reverse or letter S curve.
Oriel Window. A projecting upper story window. A small bay.
Orientation. The direction of facing of a building.
Panel. A piece of wood framed about by other pieces. It may be raised above or sunk below the face of the framing pieces.
Parapet. That part of a wall projecting above a roof.
Parting Strip. The strip in a double hung window frame that keeps the upper and lower sash apart.
Parts. The thirty equal divisions into which the module is divided for convenience.
Party Wall. A division wall common to two adjacent pieces of property.
Pendent. Usually applied to ornamental hanging parts of a Gothic vaulted ceiling.
Pendentives. The structure at the upper corners of a square building which rounds the building at the top preparatory to receiving a round dome. They may be in the form of brackets or arches.
Pent-roof. A lean-to or roof sloping one way only.
Perch. A means of measuring quantities of rubble stone. A perch contains 16 cubic feet.
Pier. A rectangular masonry support either freestanding or built into a wall.
Pilaster. When an attached pier becomes very high in proportion to its width, it is called a pilaster.
Piling. Wood or concrete posts driven down into soft earth to provide a safe footing for heavy loads.
Pitch of Roof. A term applied to the amount of slope. It is found by dividing the height by the span.
Plancher or Planceer. The soffit of a cornice or corona.
Plate. The top, horizontal timber of a wall. The attic joist, roof rafters, etc., rest on and are secured to the plate.
Plinth. The block that forms the bottom member of a column base.
Plumb. Vertical; parallel to a plumb line.
Podium. The die or body of a continuous pedestal.
Porch. A covered shelter on the outside of a building.
Priming. The first coat of paint or varnish, mixed and applied so as to fill the pores of the surface preparatory to receiving the subsequent coats.
Proscenium. The front part of a theater stage including the arch over the stage.
Pulley Stile. The vertical sides of a double-hung window frame on which are fastened the pulleys for the sash weights.
Purlins. Structural members spanning from truss to truss and supporting the rafters of a roof.
Quoins. Large cut stones at the corners of a masonry wall. They form an ornamental corner and also a stoppage for the stone or brick work of the wall proper.
Rail. The horizontal top member of a balustrade. Also the horizontal members of windows and doors.
Raking. Inclined from the horizontal.
Random Work. Applied to stone work that is not laid up in regular order but just as the stones come to hand.
Rebate. A recessed angle to receive a window or door frame, etc.
Regula. The plane block beneath the triglyph and taenia of the Doric Order.
Relieving Arch. A masonry arch built over an opening to support the backing of a wall when the wall face is carried by a lintel.
Reredos. The screen behind an altar.
Return. The turning back of a moulding, belt-course, etc., into the wall on which it is located or around a corner of the building.
Reveal. The projection of a frame or moulding beyond the wall which carries it. Also the jamb of a window or door frame between the window or door and the face of the wall.
Ridge. The top edge of the roof where two slopes meet.
Rostrum. An elevated speaker’s platform.
Rotunda. The circular space under a dome.
Roughcast. Stucco when thrown against the wall to form a rough finish. Sometimes applied to roughly troweled work.
Rubble. Roughly broken quarry stone.
Rubrication. The coloring of a background by paint, enamels, etc.
Saddle. A small double-sloping roof to carry the water away from the back of chimneys, etc. Also known as a cricket.
Salon. A large and magnificent room.
Scagliola. A plaster imitation of colored marble.
Scamillus. The groove which separates the hypotrachelium or necking of the Greek Doric column from the shaft.
Scantling. A piece of framing timber about 2 by 4 inches in section.
Scarfing. A method of lap-jointing of timbers in such a way that the joint is no larger than the section of the timbers.
Scratch Coat. The first coat of plaster which is scratched or scored to form a good bond for the second coat.
Screeds. Strips of plaster about 8 inches wide and the depth of the first two coats, which are put on first and trued up carefully to serve as guides in bringing the plastered surfaces to true planes.
Scribing. To mark or fit one edge of a board, etc., to an irregular surface.
Shaft. That part of a column between the capital and the base.
Sheathing. The rough boarding on the outside of a wall or roof over which is laid the finished siding or the shingles.
Shoring. Timbers braced against a wall to form a temporary support where it is necessary to remove the wall below.
Show Rafter. A short rafter, often ornamented, where it may be seen below the cornice.
Sill. The stone or wood member across the bottom of a door or window opening on the outside of the building. Also the bottom timber on which a building frame rests.
Site. The location of a building.
Skew-back. The first stone of an arch, having a horizontal bottom and a sloping top face.
Sleepers. The timbers laid on a firm foundation to carry and secure the superstructure.
Slip Joint. A joint made so as to allow a certain amount of movement of the parts joined without splitting or otherwise injuring them.
Smoke Chamber. That part of the flue directly above the fireplace.
Soffit. The underneath surface of a beam, lintel, arch, roof overhang, etc.
Soil Pipe. The branch pipe that connects the toilet or urinal with the soil stack.
Soil Stack. The vertical pipe line that leads from the soil pipe to the house drain.
Span. The distance between supports of a joist, beam, etc.
Specifications. The written or printed description of materials, workmanship, etc., that accompany the working drawings of a building.
Standing Finish. The wood finish secured to the walls.
Stile. The vertical members of a built up part such as a door, window, panel, etc.
Stool. The wood shelf across the bottom and inside of a window.
String. The supporting timber at the end of stair steps.
Stucco. Cement plaster for outside work.
Style (of architecture). The distinguishing characteristics as fixed by the Order used or by the type of roof, windows, doors, walls and other details in combination.
Stylobate. The stepped base of a Greek temple.
Sump. A depression in a roof, etc., to receive the rain water and deliver it to the down-spout.
Taenia. The flat division band between the architrave and the frieze of the Doric Order.
Templet. A pattern for use in cutting irregular stones such as the voussoirs of an arch, etc.
Terrace. A raised bank of earth.
Terra Cotta. A burned clay of fine quality, much used for ornamental work on the exterior of buildings.
Thimble. The short horizontal pipe leading through a chimney wall into the flue.
Threshold. The stone, wood or metal piece directly under a door.
Throat. The opening from a fireplace into the smoke chamber.
Tongue. A projecting bead cut on the edge of one board to fit into a corresponding groove on the edge of another piece.
Tracery. Ornamental curving bars across an opening. They usually occur in Gothic buildings and are cut from stone.
Transom. The horizontal member which divides an opening into parts; It is also applied to a small window built over a door.
Transom Bar. Same as the first use of Transom.
Trap. A water-seal in a sewage system to prevent sewer gas from entering the building.
Tread. The horizontal board or surface of a step.
Trellis. An ornamental lattice made up of wooden strips to support vines.
Triglyph. A grooved plate, ornamenting the frieze of the Doric Order.
Trim. The finishing frame around an opening.
Trimmer Arch. The supporting arch beneath a hearth.
Truss. A framework made up of triangular units for supporting loads over long spans.
Tympanum. The triangular portion of wall under the sloping cornice of a classic building.
Underpinning. A new part of a wall or pier, built under an existing part.
Valley. The gutter formed by the intersection of two roof slopes.
Valley Rafter. The rafter extending along under a valley.
Vault. An arched ceiling or roof.
Veneer. A thin covering of valuable material over a less expensive body.
Vent Pipes. Small ventilating pipes extending from each fixture of the plumbing system to the vent stack.
Vent Stack. The vertical pipe connecting with the vent pipes and extending through the roof. It carries off the gasses and prevents the water-seal from siphoning out of the traps.
Verge Boards. The boards suspended from the verge Waste Stack. The vertical pipe which conducts waste of a gable. They are sometimes highly ornamented. water from the waste pipes to the house drain.
Vestibule. A small entrance room.
Vista. A view down an avenue or a path between building near the ground to throw the rain water away shrubbery, etc. from the wall.
Volute. The rounded or spiral end of a stair railing. A feature of the Ionic capital.
Voussoir. One of the sections or blocks of an arch.
Wainscot. An ornamental or protective covering of main part, walls, often consisting of wood panels.
Wreath. The curved portion of a hand rail as at a Wall Plate. landing.
Waste Pipe. The pipe connecting lavatories and sinks.
Yoke. The horizontal top member of a window frame, with the waste stack.

We hope this glossary has helped clarify architectural terms. If you want to dive deeper, consider exploring architectural design guides or reaching out to professionals for hands-on knowledge.