Planning Library

Built Heritage Glossary

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AbacusThe uppermost part of the capital of a column, usually parallelepiped shaped. The architrave rests on top of the abacus.
AbbeyA collection of buildings such as church or cloisters that compose a monastery complex ruled by an abbot.
AbutmentA structure that supports the lateral thrust of an arch or vault. (See also ‘Arch’ and ‘Vault’).
AediculeIn Greek Architecture, the Aedicule is an opening (door or window), framed by columns with a pediment. (See also ‘Pediment’).
AggregateMaterial such as sand or small stones used, when mixed with a binder and water, to form a mortar or concrete.
AmphitheatreAn arena surrounded by tiered seating from the Roman Era.
Anaglyptic PaperAn embossed, decorative paper used on walls, dados and ceilings, particularly popular in the late Victorian period.
Anchor PlateA plate, usually metal, fixed to the face of a wall and to which the ends of structural reinforcement, or tie bars, are bolted. Also referred to as a ‘Tie Plate’.
ApexThe uppermost point of a cone or triangle.
ApronA panel below another significant feature, particularly the area of wall beneath a window.
ArchA curved architectural element which spans an opening and also serves as a support. Depending on the symmetry of the shape of the arch, they fall under different categories such as: rounded, pointed or Tudor arches.
ArchitraveIn classical architecture, the lowest part of an entablature immediately above the columns. The term is also commonly used to describe a moulded surround to an opening, covering, or the joint between the door or window frame and they wall face.
ArrisA sharp edge at an external angle, produced by the meeting of two surfaces.
Art DecoA term used to describe a decorative style popular in the 1920s and 1930s, identified with the jazz age and characterised by strong geometric design.
Arts and CraftsAn architectural, artistic and social movement which started in England by William Morris in the mid-nineteenth century, to revive the traditional skills of the medieval craftsman and to encourage the use of local materials.
AshlarCut stone worked to even faces and right-angled edges and laid in a regular pattern with fine joints.
BalconetteA small iron balcony fixed to a window sill for either decorative reasons or to hold a window box or plant pots.
BalusterA small pillar/column supporting a rail.
BalustradeA series of balusters.
BargeboardInclined board fixed at the gable end of a roof to cover and protect the ends of the roof timbers. Highly decorated in some styles of architecture.
BayA section of a building distinguished by vertical elements such as columns or pillars.
Bell-cote A small housing to hold a bell.
Blocking CourseThe course of masonry erected above a cornice to visually and structurally anchor it.
BraceA timber or steel element, set diagonally between two structural members, to strengthen the joint or to reinforce a structural frame.
BracketAn element designed to support, or to give the appearance of support to, a projecting weight. Some brackets are also called 'corbels' and in Classical architecture are referred to as 'Consoles'.
ButtressA reinforced projecting wall acting in compression, usually on the exterior of a building.
CamesGrooved metal strips, usually of zinc or lead, holding glass pieces together in lattice or patterned glazing or in a stained-glass window.
CasementA window frame hinged at one side to open like a door.
Cast IronAlso known as 'Pig Iron’, this is a ferrous metal formed by pouring into moulds which allows it to be made into decorative panels. Cast iron is also used for structural elements but, while it performs well in compression, it is weak in tension.
CementA binding material mixed with aggregate and water to form a mortar or concrete. The term is usually taken to mean an artificial cement such as 'Portland Cement'.
CheekThe vertical side of a dormer window.
Coade StoneA ceramic material manufactured by Mrs Eleanor Coade and her daughter in Lambeth between 1769 and c.1840. It was widely used in the late eighteenth and early nineteenth centuries in architectural ornament and has proved extremely durable.
Column An upright pillar, usually circular in shape whic provides structural support for an arch, entablature or other stucture. A column can also be free standing.
ConcreteA strong quick-setting material made from cement, aggregate and water. Concrete can be cast in situ or in precast units. It can be used alone as mass concrete or cast around steel rods to increase its tensile strength, when it is known as ‘Reinforced Concrete’.
ConsoleA carved or moulded bracket used in classical architecture.
CopingA capping or covering to the top of a wall to prevent water entering the core of the wall.
CorbelA projecting cantilevered block supporting elements over it such as a floor beam or truss.
CorniceIn classical architecture, the highest projecting part of an entablature resting on the 'Frieze'. The term is also commonly used to describe any moulded decoration marking the junction between the wall and ceiling.
Cottage OrnéA picturesque, rustic house usually built to an asymmetric plan form and characterised by decorative timber features and elaborate thatched roofing. In Ireland, this building type usually dates to the first half of the nineteenth century.
CovingA concave treatment of plaster at the junction between walls or ceilings.
CrampA metal strap or pin built into a wall to hold together elements such as adjacent blocks of stone.
CrestingAn ornamental finish, usually of iron, along the top of a screen, wall or the ridge of a roof. Sometimes known as ‘Ridge-combs’ when formed in terracotta.
CupolaIn classical architecture, a small domed structure on top of a dome or a roof.
CurtilageThis word is defined under different terms. In a general sense 'curtilage' refers to the land and area enclosed around or within a house.
DadoThe lower panelled portion of an internal wall, often surmounted by a moulded chair, or dado, rail. The dado rail was often used on its own, without the panelling below.
Damp-Proof CourseSee 'Architecture' glossary.
DemesneThe part of a historic estate associated with a country house, which was reserved for the personal use and enjoyment of the owner.
Door LeafThe openable part of a door. It may be connected by side hinges to a frame or slide horizontally.
Dormer WindowSee 'Architecture' glossary.
DovecoteA building housing pigeons or doves usually with small perching niches in the walls. Often a feature of country house estates.
DownpipeSee 'Architecture' glossary.
Dry RotThe common name for the fungus ‘Serpula lacrymans’ which feeds on damp timber in poorly ventilated spaces, causing the timber to lose strength and to develop characteristic cracking.
Eaves See 'Architecture' glossary.
Electro-OsmosisA system to prevent rising damp within a masonry wall, consisting of anodes inserted into a wall and linked by earthed wires along the base of the building. A small electric charge running through the system is intended to have the effect of repelling water molecules rising through the wall.
EnfiladeA suite of rooms, with aligned doors, opening off each other in sequence, which creates a vista through the rooms when all doors are open.
EntablatureThe upper part of a classical order, supported by columns or pilasters and consisting of three horizontal bands: 'Architrave', 'Frieze' and 'Cornice'.
EscutcheonA cover plate for a keyhole.
FaïenceGlazed terracotta used as decorative cladding and usually fixed to the interior or exterior of a building in flat or moulded panels.
FanlightA semi-circular or semi-elliptical glazed area above a door. A similar rectangular feature is generally called an ‘Overlight’.
FasciaA horizontal board. Usually given to the name-board above traditional shopfronts or to the flat vertical board that protects projecting ends of roof rafters at the eaves and to which the gutter can be fixed. Traditional eaves detailing in Ireland does not use fascia boards.
FinialAn ornamental capping to a pinnacle, spire, gable etc.
Fire MarkA plaque or plate issued by insurance companies and fixed to buildings to enable an insurance company to identify buildings insured by it. In Ireland fire marks usually date to the eighteenth and nineteenth centuries.
FireskinThe protective outer layer formed during the firing process on the surface of bricks and terracotta units.
FlashingSee 'Architecture' glossary.
Flitch BeamA timber beam with an inserted metal plate (flitch plate) to reinforce its structural strength.
FollyA decorative building erected in a designed landscape often with no specific purpose other than to be viewed as an eye catcher.
French DrainA trench filled with gravel or other loose material to collect ground water and deflect it away from a building.
French Window A pair of glazed external doors usually leading onto a garden, terrace or balcony.
FriezeThe central portion of a classical entablature located below the cornice and above the architrave, which can be plain or decorated.
GableSee 'Architecture' glossary.
GalletsAlso known as 'Pinnings’ or ‘Spalls’. Small pieces of stone or other material pressed into the mortar joints of a wall either as decoration or to reduce the amount of mortar required and to reduce the danger of shrinkage.
GargoyleA projecting water-spout designed to throw rainwater from a roof away from the wall. Often carved into grotesque heads of human or animal figures.
Gauged BrickworkPrecisely-made brickwork laid with fine joints often of pure lime putty.
GessoIt is a white paint which is made from a binder mixed with gypsum/chalk/pigment or a combination of all. It was used in the late eighteenth and early nineteenth centuries to add ornament to timberwork.
GrainingA decorative paint technique imitating the grain of timber. It can also be referred to as 'Scumbling'.
Ha-HaA ditch with one vertical side and one sloping side used in landscape design as a means of containing livestock while maintaining an uninterrupted view.
HaunchingThe building up of a mortar fillet around an element such as a pipe or the base of a column.
Hipped RoofSee 'Architecture' glossary.
Hopper HeadA receptacle for collecting rainwater from gutters and channelling it into downpipes.
IcehouseAn underground or semi-underground chamber built to store ice or snow throughout the summer and to provide a cold store to keep food products fresh. Usually associated with a large country house estate.
IndentingThe process of replacing a damaged stone or part of a stone by inserting a piece of new matching stone.
IronmongeryThe hardware associated with a door or window such as locks, hinges, handles etc.
JoistsSee 'Architecture' glossary.
Jostle StonesUsually cylindrical stones set adjacent to the corners of buildings or gateways to protect from damage by the wheels of passing vehicles. Also known as ‘Wheel Guards’.
KeystoneThe central stone of an arch, sometimes prominently decorated.
KneelerThe larger stone at the base of a gable which restrains the inclined coping stones above it and keeps them in place. Also known as a ‘gable springer’.
LathsThin strips of wood, often chestnut or oak, forming a base for plaster.
Lime-AshA floor-covering formed using the residue from the bottom of a lime kiln after firing, combining it with gypsum and water to produce a composite material which, when laid over a bedding material, forms a hard and durable flooring material usually for the upper floors of a building.
Lime (Hydraulic) Hydraulic lime contains a percentage of clay which produces a pozzolanic effect in mortars, that is, the mortar is set by its chemical reaction to water. Hydraulic limes can be naturally occurring or can be artificially made.
Lime MortarA mortar made from lime putty, aggregate and water that, on exposure to air, carbonises and hardens.
Lime (Non-Hydraulic)Non-hydraulic limes are pure, or almost pure, lime. Mortars made of non-hydraulic limes can only set through contact with air, a process known as carbonation.
Lime PuttyA soft putty made from slaking quicklime in water. Used as a binder in most traditional mortars and renders prior to the invention of Portland cement.
LimewashA form of thin lime putty used as a paint or protective coating. It differs from 'Whitewash' which is a mixture of chalk and water that does not carbonate.
LintelSee 'Architecture' glossary.
LouvreSee 'Architecture' glossary.
LychgateA covered, usually timber, gateway with open sides at the entrance to a churchyard which traditionally provided a resting-place for a coffin.
Mansard RoofSee 'Architecture' glossary.
Mason’s MarkA symbol or initial cut into stonework by the mason executing the work. Usually associated with mediaeval masonry.
MewsSee 'Architecture' glossary.
Modern MovementA functional undecorated style of architecture associated with the first half of the twentieth century.
MortarSee 'Architecture' glossary.
MullionSee 'Architecture' glossary.
Nail SicknessThe widespread failure of the nails holding roof slates in place, usually due to rusting.
NewelSee 'Architecture' glossary.
NoggingThe infilling between timber studs in a partition to strengthen and stiffen them.
NosingSee 'Architecture' glossary.
Oriel Window See 'Architecture' glossary.
OverlightSee 'fanlight'.
ParapetSee 'Architecture' glossary.
Pebble-DashSee 'Architecture' glossary.
PedimentIn classical architecture, a form of decorative treatment of a gable, often with sculpture to its tympanum. Although usually triangular, can also be arched or segmental. Also used above door and window openings.
PilasterA flat column-like projection from a wall with the profile of the orders of the classical language of architecture and carrying an entablature.
PinningsSee 'gallets'.
PlasterA surface covering for internal walls and ceilings. Traditionally made of lime, sand and water, sometimes reinforced with animal hair or straw and applied wet.
PlinthThe projecting base of a wall or column.
PorticoA covered, open entrance in a Classical composition, with columns supporting the roof. It is often surmounted by a 'Pediment'.
Portland CementAn artificial cement invented by Joseph Aspdin in 1824 and so called because of its perceived resemblance to Portland stone. It sets rapidly and is very hard when set.
PuggingA coarse material, usually sand or mortar, added between the joists of a timber floor or the studs of a timber partition to enhance sound insulation.
QuarryIn leaded-light glazing, a small square or diamond-shaped piece of glass.
Quarry SapThe moisture found in newly quarried stone which makes it easier to work.
QuoinA dressed stone forming the corner of a building, often decorated or raised.
RafterSee 'Architecture' glossary.
Reconstituted StoneA type of precast concrete which uses as aggregate a large percentage of stone particles.
RedressingThe cutting back of a material, usually stone, to a new surface.
RenderA mixture of a binder (such as lime or cement), an aggregate and water to form a coarse plaster which is applied to the external surfaces of walls (see also ‘Roughcast’).
RepointingThe act of replacing mortar in the face joints of brickwork or stonework following either the erosion of the original mortar or its removal through raking out.
RevealsSee 'Architecture' glossary.
Ridge See 'Architecture' glossary.
Ridge-Combs See 'Cresting'.
RoughcastA render covering for an external wall which is applied by throwing the mixture onto the wall. Also known as ‘Wet Dash’.
Rubble Masonry Walls made of rough unworked stones, often field boulders, of irregular size and shape. The stones can be laid completely at random or brought to courses.
RusticationIn classical architecture, the treatment of a wall surface with strong texture. In ashlar, rustication is often achieved by forming deep grooves in the joints or by working the surface of the stone.
Sash WindowA sash is one of a pair of glazed frames which slide past each other within a frame. The sashes can slide either vertically or horizontally but vertically sliding sash windows are by far the more common in Ireland, and are usually counterbalanced using pulleys and weights.
ScagliolaA composition of gypsum or sulphate of lime made to imitate marble.
ScarfingThe uniting of two pieces of timber to form a continuous length without increasing the depth or width of the beam at the joint.
SettA rough-hewn cube of stone or timber used for paving.
ShakeA timber roof tile, usually of oak or cedar, split along the fissures radiating from the centre of a piece of timber.
Shelter CoatA sacrificial coating of limewash or thin render applied to a surface to protect it from deterioration.
ShingleSee 'Architecture' glossary.
Sill GuardsA metal obstacle, sometimes decoratively treated, fixed to a ground-floor windowsill to prevent its use as a seat or to protect it from accidental damage.
Size/SizingA liquid sealant for coating wood or plaster to prevent paint or varnish applied over it being too much absorbed into the substrate.
SolderAny easily melted alloy used for joining metals.
SpallingThe breaking away of small chips or flakes of stone or concrete.
SpandrelA triangular panel in the corner between a vertical and horizontal structural member.
SpecificationSee 'Architecture' glossary.
SplicingThe letting-in of a small piece to repair a damaged element of joinery.
String CourseSee 'Architecture' glossary.
StrutSee 'Architecture' glossary.
StuccoA plaster containing gypsum, lime and marble powder. It can be used externally to imitate ashlar or internally in ceiling or wall decoration.
StudSee 'Architecture' glossary.
TerracottaTranslation meaning ‘burnt clay’, the term is usually used to describe a more finely grained ceramic than brick or tile and is used for wall facings, chimney pots and the like.
TerrazzoA hard flooring material containing marble chippings mixed with cement which is laid in situ, then ground and polished to a smooth finish.
TieSee 'Architecture' glossary.
TraceryOrnamental intersecting timber or stone mullions and transoms in a window, panel or vault. Typical of the Gothic or Gothic-Revival styles.
TransomSee 'Architecture' glossary.
Tread EndThe vertical surface to the side of a step in a staircase, sometimes decoratively finished with moulded or carved work.
TrussSee 'Architecture' glossary.
Tuck-PointingA decorative form of pointing giving the effect of gauged brickwork. The joints are filled with a mortar matching the colour of the brickwork. A thin groove or tuck is then cut into the mortar and filled with white lime putty.
TympanumThe area enclosed within a pediment, or the space between lintel and arch above, often carved or decorated.
VerandaAn open gallery or balcony on the outside of a building with a roof supported on light timber or iron posts.
VergeSee 'Architecture' glossary.
VoussoirA wedge-shaped stone or brick forming part of an arch. The middle voussoir is called a keystone and is often carved and decorated.
Wall PlateA horizontal timber piece laid along the top of a wall to receive the ends of the rafters.
Wet RotA generic term for fungi which feed on wet, or sodden, timber causing it to soften and lose strength.
Wheel-GuardsSee ‘Jostle Stones’.
WicketA small door or gate set within a larger one to allow pedestrian access while avoiding the need to open the full door or gate.
Wrought IronA ferrous metal smelted and then worked, or wrought, by hammering. Much used for elements such as railings and gates. It can also be used for structural members but while it performs well in tension, it is weak in compression.


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