Glossary of Architectural Terms

Ashlar masonry
Squared blocks of stone laid in courses. Random ashlar employs blocks of varying sizes laid together. Coursed ashlar employs equal sized blocks in regular courses.
Baluster
Vertical members supporting a cap rail or hand rail forming a balustrade.
Bay
A vertical division of a building marked by fenestration.
Bay window
An angular projection from the building face filled with fenestration.
Bellcast
A curve built into the bottom edge of a roof surface or a wall surface.
Bracket
A support, often scroll-shaped, supporting an overhang.
Bulkhead
A small panel at the ground level of a storefront window or opening; usually of decorative tile or wood.
Capital
The head of a column, sometimes carved in one of the classical orders.
Clinker brick
Bricks of irregular quality, damaged during the firing process, used for their picturesque effects.
Column
An upright member, usually rounded, consisting of a base, shaft, and capital.
Coping
A protective capping to a wall.
Corbel
A projecting block, supporting an overhang.
Corbelling
Masonry courses, each built out from the one below.
Cornice
A projection crowning a wall surface.
Dentil
Small square blocks in series that decorate a cornice.
Dormer
A structure projecting from the slope of a plane of a roof; a hipped dormer has a roof sloping to all three exposed sides, a gable dormer has a roof sloping to two sides, and a shed dormer has a single pitched roof.
Drop finial
A carved ornament on a roof line or at a roof crest, pointing down.
Drop siding
Weather boarding with a deep groove on the top outer edge that fits into a slot on the rear bottom side of the board above.
Eave brackets
Brackets, often decorative, under the lower edge of a roof.
Eaves
Horizontal roof edges.
Facade
The front face of a building.
False front
A false facade applied to a building to increase its street presence.
Fascia
A plain horizontal band, as part of a cornice string course.
Fenestration
The design and disposition of windows and openings in a structure.
Finial
An ornamental termination at the top of a gable or pinnacle.
Flashing
The metal protective cap at the top of a wall, or a weatherproof strip at a roof edge.
Gable
A roof pitched to two sides, oriented to either the front or side; variations include hip-on-gable (also known as a half-hipped, hipped or jerkin-headed roof).
Gable screen
Wooden members arranged in an open-work pattern in a gable end.
Gambrel roof
A dual pitched gable roof with a shallower slope above a steeper one.
Half-timbering
Wooden members, infilled with plaster; a decorative treatment derived from medieval heavy timber construction.
Hammerbeam
A truss roof system, supported on corbelled blocks projecting from the wall.
Head
The top of a structural opening.
Hip
A roof with all four sides sloped.
Jerkin-headed
A gable roof end with a half hip; see gable.
Keystone
The central member of an arch, usually the most prominent, often carved.
Leaded glass
A window pane composed of smaller pieces of glass, held together by lead cames; usually straight or cross-leaded.
Lintel
A horizontal beam bridging an opening.
Mullion
A divider or upright that sections a window into lights.
Oriel window
A bay window projecting from an upper storey.
Parapet
The extension of a wall or railing above a roof line; subject to a variety of decorative treatments.
Pediment
A triangular feature over a structural opening, or capping a wall.
Pilaster
An engaged vertical segment.
Pitch
The steepness of a roof.
Porch
A covered entry to a building.
Purlin
A longitudinal roof member perpendicular to the rafters.
Rafter
A roof member sloping from the wall plate to the ridge.
River rock
A naturally rounded stone; sometimes called cobbles.
Reveal
The surface at the side of an opening indicating the thickness of a wall.
Rubble masonry
Walls made with rough uncut stones of varying sizes.
Saddlebag dormer
A pair of low-slung shed roof dormers, one on each side of a roof ridge.
Sidelights
Narrow vertical windows beside an entry door.
Sill
The horizontal base element of a window or door.
Soffit
The underside of an architectural feature, usually a cornice.
Spandrel
The panel between the head of one window and the sill of the window immediately above. Alternately, the triangular area contained by one side of an arch.
Stained glass
Coloured or painted glass panels, usually assembled with lead cames.
Stair cheeks
The solid exterior sides of a staircase.
Stringcourse
A continuous projecting horizontal band or course, running horizontally around a facade; also known as a beltcourse.
Surround
A border to an opening or a panel.
Terra cotta
Fired masonry units, usually glazed; translates literally as burnt earth.
Transom
A horizontal bar dividing a window; alternately a crosspiece dividing a door or window from a panel, or fanlight above it, within the same structural opening. Also the window above such a crosspiece.
Twin-coursed shingles
Rows of cedar shingles with alternating narrow and wide exposure.
Verandah
An open gallery, usually supported on a row of columns.
Verge Boards
Facing boards, often decorated, hung from the projecting edge of a sloping roof; sometimes called "barge boards."