Glossary of terms

The following listing is based on Historic Scotland’s Glossary of Architectural terms at and augmented with additional architectural, art and design terms.

Following the design principles or details used by the 18th century family of classical architects, William, John, James and Robert Adam.

The lowest of the three main divisions of the classical entablature, varying according to the order employed; moulded surround to an opening or recess.

Sharp edge at the meeting of two surfaces.

Art Deco:
A style of visual art, architecture and design taking its name from the ‘Exposition Internationale des Arts Decoratifs et Industriels Modernes’ held in Paris in 1925. Its distinguishing features are sleek stylised forms often with a streamlined look. The period lasted from the 1920s through the 1930s.

Art Nouveau:
A style of art, architecture and applied art inspired by matural forms such as the sinuous curves of plants and flowers often using modern materials such as iron, glass and ceramics. It was popular between 1890 and 1910.

Arts and Crafts:
Style of design focusing on craftmanship, material quality, use of local material, often reviving vernacular or traditional forms.

Masonry of large blocks in regular courses worked to even faces and carefully squared edges: the stones themselves are called ashlars and may have a dressed finish.

Wooden glazing bar used to support the glass panes of a window.

A parapet or stair rail composed of uprights supporting a coping or rail.

Band Course:
Masonry band which encircles a building wholly or in part usually unmoulded.

Boards placed at the incline of a gable to hide the ends of the roof timbers, often decoratively treated.

The lowest moulding of any structure.

The inward incline of an external wall surface, usually at the base, the thickness of
the wall being progessively diminished.

A vertical alignment of key elements in a wall such as doors or windows which may also project or recess.

Beton Brut:
Raw concrete left in its natural state after the formwork has been removed, also known as board-marked concrete.

Blocking Course:
Plain course forming a low parapet above a cornice usually screening a gutter.

In roofs, the ornamental cresting of cast or wrought-iron crowning a roof, but sometimes also found applied to cornices and other ornamental features.

Of masonry, stonework worked to a horizontally or diagonally furrowed surface; usually on ashlar with a margin draft at the edge.

Architectural style appearing in the 1950s and 1960s featuring exposed concrete and emphasising bold structural forms.

Canted Bay:
A canted bay window has a flat front and angled sides. The number of bays is defined by the number of windows in a horizontal line across the façade.

The crowning element of a column, colonette or pilaster, usually moulded or sculptured.

In windows, a side-hung hinged light.

Very narrow face created when an arris is cut at an angle, usually 45 but sometimes hollow (ie concave) or ovolo.

Cherry Caulking:
Treatment of masonry joints in which small stones are inserted into the mortar.

The external housing at wallhead of chimney flues.

Passageway giving access to a number of houses or buildings; in an urban context usually but not always pedestrian, in steadings used as vehicular passage or pend.

Upright structural member, usually circular in section.

Greenhouse or glazed extension as garden room.

The projecting uppermost member of the classical entablature; in isolation used as the crowning feature of external walls, or as the demarcation of an attic storey; or at windowheads, over shops etc; and internally at the junction of wall and ceiling.

A stepped arrangement at the head of a gable leading to a chimney stack or gablehead.

A building, wall or archway which has battlements /castellation.

Form of vernacular roof construction in which the roof is carried on pairs of naturally curved timbers or crucks joined at the ridge and combining the functions of upright post and rafter (full crucks) or embedded into the wallhead (upper crucks).

A small dome like structure on top of a building, crowning a roof or dome. Often used to provide lookouts or admit light and air into the interior of a building.

The lower portion of an internal wall above the plinth or skirting board and beneath the dado or chair rail, sometimes of plaster but often panelled timber.

Dentil Course:
Member of cornice below the main projecting member composed of rectangular blocks tightly spaced like teeth.

Dovecot or pigeon house.

Window breaking above the eaves at wallhead or set in the roof.

Of masonry, horizontally furrowed finish, usually on ashlar, popular in later 18th and early 19th centuries. See also broached.

Dry Dash:
20th century method of harling in which the aggregate is dashed on dry, and not incorporated into the mix (see also harl).

Overhanging edge of a roof.

Collective name for the three horizontal members (architrave, frieze and cornice) above a column, in treatment, as a division between storeys or as an impost band at an arcade.

Glazed area above door; if rectangular rather than semi-circular, semi-elliptical or segmental, more correctly a transom-light.

The windows of a property.

Spirelet of timber and lead rising from a roof ridge rather than a tower.

External stone stair, usually to 1st floor level.

Small gable-shaped feature over an opening or recess.

Scottish form of roughcast in which the mixture of the aggregate (small even- sized pebbles) and binding material (in traditional harl, sand and lime) is dashed onto masonry wall; in traditional harls the aggregate is in the mix (wet dash) non-traditional 20th century harls the aggregate is dashed on seperately (dry dash).

Projecting moulding over an arch or lintel designed to throw off water.

Small upstands or downstands in windows from the meeting rails at the vertical members of the sash frame.

Horse Mill:
Circular or polygonal building built to contain machinery driven by horses (horse engine), usually for the purposes of a threshing machine.

Ice House:
Vaulted or domed chamber banked over with earth which was filled with ice for domestic or commerical purposes.

Style of simple cubic modern asymmetrical designs, usually white and unadorned, Style characterised by windows in horizontal bands and open ground plans.

In a mill, kiln barn or maltings building, that part of the building used for drying grain, identifiable by its having a furnace, a funnel leading to a metal floor and a vent in its roof.

Treatment of overlapping boards angled to allow ventilation but to keep the ran out; used at belfry stages, persiennes, tanneries, barns etc.

Lying Panes:
Panes of glass which are horizontally rather than vertically proportioned, fashionable in the period 1815-50.

Mansard Roof:
Four-pitch roof with a steep lower pitch and a shallower upper pitch on each side.

Margin framing an opening or emphasising the angle of a building; most are raised (usually adopted when the building was to be harled but sometimes used decoratively) but some are chamfered and some are backset (ie recessed from the plane of the harl or render).

Stabling, in an urban context.

Small bracket, sometimes scrolled, sometimes block-like, set at regular intervals in the soffit of a cornice.

Upright member dividing the lights of a window.

Small flat slabs at the soffit of the cornice of a Doric entablature and positioned above the triglyph, if any; often used as a wallhead cornice without full entablature.

Double curve composed of two curves in opposite directions without a break; used on both roofs and arches.

Classical form of corniced gable or gablet used at openings as well as a termination to roof structures.

Open-ended passageway through a building; usually vehicular (as against a close which is usually pedestrian).

Hipped roofed.

The flat version of a column, consisting of a slim rectangle projecting from a wall; used also as plain piers or pilasters without classical orders which are more correctly termed pilaster strips.

Slender vertical posts supporting overhanging architecture, charcteristic of Modern Movement design post-1945.

Large sheets of glass cast in plates and polished, introduced from 1838 onwards.

Platform, broad doorstep, landing on stair, cantilevered stone gallery access to tenement flats.

The treatment with mortar of exposed joints in masonry or brickwork.

Stones larger than those of which a wall is composed, or better shaped, and forming the corners of walls or door and window openings: if they project they are described as raised, those with chamfered angles being referred to as rusticated.


Smooth coating of cement over masonry.

The inward plane of a door or window opening between the edge of the external wall and the window or door frame.

Masonry which is not fully dressed; can be of boulders; or of random rubble retaining in some degree the natural shape of the stone; or of squared rubble in which the stones are roughly squared and may be either coursed or snecked. Variations in the coursing is brought about by the use of small filler stones or snecks.

Treatement of masonry in which the joints are sunk, usually in a V (chamfered rustication) but sometimes square; can have varied decorative treatments, eg with rock redded or vermiculated panels, or frosted in which the blocks appear as coated icicles.

Sash and Case:
Form of window in which the glazing slides vertically in two parrallel frames  within the case, the upper sliding outward of the lower.

Sloping tabling, sometimes coped, finishing a gable which is upstanding from the plane of the roof.

Bottom end of skew or crowstepped gable which projects from the wallhead, usually in a cavetto.

Form of rubble construction composed of squared stones in which the coursing is varied by small filler stones or snecks.

The underside of a cornice, stair or lintel; that of an arch is more correctly an intrados.

Stall Riser:
In a shopfront, the panels below the display window’s cill.

A shallow moulding continued across a whole facade which may be defined by Course its position, eg cill course or impost course.

Of masonry stone work, its surface picked to a consistent pattern, commonly employed from the mid-19th century onwards.

Roof window formed by sweeping a section of the roof up from the main plane Dormer at a slacker pitch; also known as a catslide dormer.

System built:
Term used for pre-fabricated, mass-produced construction post-1945.

Stone weathering projecting over the roof cladding at the base of a chimney, in its original use over thatch.

Pattern of pierced open stonework in a Gothic or early Renaissance window; in Georgian or post-Georgian buildings may be of wood and may even be part of a window sash.

Horizontal member dividing a window opening.

The triangular frames bearing a roof.

Open shelter or gallery around a building with a lean-to roof carried on verticals of timber or iron.

Form of wall cladding composed of overlapping horizontal boards on a timber framework.

Wet Dash:
Traditional type of harl in which the aggregate of small, evenly-sized pebbles is incorporated into the mix.