Planning service

Glossary of planning terms


Amenity space - areas of open space such as gardens, balconies and roof terraces.

Appeal - the right of an applicant to seek a review from the Secretary of State of a decision made by the local planning authority in respect of an application. Appeals can be made following a refusal of permission or after the expiry of the legal period if the local planning authority has failed to make a decision. Appeals can also be made in respect of conditions attached to a grant of permission.

Arch - a section above a door or window with the structural function of dispersing the weight from above around the opening. Also referred to as a head above a door or window. The shape will determine its name; most common are segmental (semi-circular), lancet (pointed) and gauged (composed of shaped bricks).

Architrave - in Classical architecture, the lower part of a moulded cornice. Commonly used term for the moulded surround of a door or window.

Art Deco - an artistic movement of the 1920s and 30s characterised by clean, sharp lines and less sinuous motifs than Art Nouveau.

Article 4 Direction - the power given to a local planning authority to take away specific permitted development rights and require a planning application to be submitted.

Article 14 Direction - a power given to the Secretary of State to serve notice on a local planning authority preventing it from granting permission for a particular planning application while he or she considers whether the application should be "called-in".

Arts and Crafts - derived from an artistic movement of the late C19, based on the ideas of William Morris, which promoted traditional forms of design and the use of craft techniques in construction. Its architectural expression is seen in the use of traditional materials and restrained vernacular decoration.

Art Nouveau - an artistic movement of the turn of the century characterised by stylised forms of flowers and animals, prevalent in Edwardian buildings.

Ashlar - smoothed even blocks of stone masonry.

Atrium - glazed courtyard often extending through several floors at the entrance to a building.


Balustrade - the upstanding part of a stair or balcony that supports a rail or coping.

Bargeboard - a timber piece fitted to the outer edge of a gable, sometimes carved for decorative effect.

Baroque - a style associated with late Classical architecture, that evolved during the C17 and C18 and is characterised by exuberant decoration overlaid on classical architectural details.

Battered - a feature, such as a chimney, with sloping faces or sides making it narrower at the top than at the bottom.

Bay - an extension to the main building line, termed canted or splayed when angled back at the sides, and squared when perpendicular.

Bond - the pattern in which bricks are arranged in a wall, e.g. stretcher bond, where all the bricks in each course are laid with their long side (or stretcher) on view; Flemish bond, alternating between a course with the long side on view and a course with the short side on view.

Bonnet - a small roof over a bay.


Call-In - a power given to the Secretary of State to enable him or her to decide a particular application in lieu of the local planning authority.

Cape - extension to the footpath to narrow the road width.

Casement window - a window opening on side or top hinges.

Clerestorey - a row of windows at high level lighting the ground or principal floor; very common in churches where they are positioned over the aisles.

Column - a structural or decorative vertical element, usually circular, supporting or framing the upper parts of a building.

Conservation area - an area of special architectural or historic interest, the character or appearance of which it is desirable to preserve or enhance. Normally designated by the Council.

Conservation area consent - consent for the demolition of a building (or substantial part of a building) in a conservation area.

Coping - a sloping or curved, overhanging section of stone on top of a wall or parapet designed to protect the masonry from rain water.

Cornice - a decorative mould applied to parapets and pediments.

Cupola - a domed structure on the roof.

Curtain walling - a non-load-bearing wall applied in front of a framed structure, using metal, glass or thin masonry units to form the external finish to a building

Curtilage - the area within the boundaries of a property surrounding the main building.


Dentil course - a row of small square projecting blocks used in series, with small gaps between, usually forming a cornice.

Density - the number of habitable rooms per hectare (hrph) in a residential development.

Development brief - guidance published by the Council (as Supplementary Planning Guidance) for an individual site, indicating the kind of development the Council would support and encourage, as well as any specific requirements of the Council or other bodies.

Dormer window - a window projecting from a roof.


Eaves - the lower, overhanging section of a pitched roof, intended to throw rain water away from the wall below.

Environmental impact assessment (EIA) - studies required to be undertaken by a developer in respect of some major developments to demonstrate to the local planning authority the likely impact of the proposal on the environment.


Faience - a form of terracotta, usually white, with a glazed finish, used as a cladding for walls.

Fencing - close boarded: formed of vertical wooden boards, close together or touching, attached to horizontal rails between posts; feather edge: as close boarded, but formed of overlapping boards, thicker at one side than the other (i.e. like a feather in cross section); palisade: formed of pointed stakes in wood or metal, spaced apart and leaving gaps; hit-and-miss: formed of vertical wooden boards, spaced widely on one side of the rails, with similar boards on the other side, aligned so that the gaps on one side correspond with the boards on the other; chain link: formed of interwoven wire in a diamond shaped mesh; ranch style: formed with 2 or 3 broad horizontal planks, widely separated and fixed between posts, often painted white; can be timber or plastic; larchlap or interwoven panels: formed of thin flexible strips of timber, either arranged horizontally or with vertical and horizontal strips interwoven, all contained within a lightweight frame, fixed between posts.

Fenestration - the pattern of windows.

Finial - a decorative device to finish off a building element with a flourish, most commonly seen on railings.

French window - glazed full length opening casement windows.

Frieze - a band or decorative motif running along the upper part of the wall, sometimes carved (e.g. on Wandsworth Town Hall)


Gabion - a cylinder or wide mesh basket of wicker of woven metal to be filled with earth, rubble or stone blocks to form a wall or other solid feature.

Gable - a decorative finish to the upper part of a wall designed to obscure the roof structure. Termed Dutch if replicating the style common in Holland; crow-stepped if rising in stages like a staircase.

Gauged - bricks shaped to fit together closely, as in an arch or head.

Gault brick - a light cream/yellow brick commonly made in East Anglia (hence Suffolk gaults).

Gazebo - a small building or structure such as a summerhouse, which is often open on one or more sides to give views.

Green chains - undeveloped open land providing links between larger areas of open land, for walking, cycling or wildlife corridors.


Habitable rooms - all the rooms in a flat or house other than bathrooms, W.C.s, and small kitchens.

Head - the common form of an arch over an opening.

Hipped roof - a roof sloping at the ends as well as the sides.


Juliet balcony - a shallow balcony designed to provide a safety barrier in front of french windows.


Lancet - a window or arch coming to a narrow point and much used in Gothic architecture.

Lawful development certificate - a certificate issued by the local planning authority upon application by a developer which confirms that either:

1) A proposed development does not require permission from the local planning authority or
2) Development that has already taken place either did not need permission or took place so long ago that it is immune from enforcement action.

Lightwell - an opening within or next to a building that allows natural light to reach windows that would otherwise be obscured, e.g. within a basement.

Lintel - a structural beam above an opening, such as a window or door, which may be expressed externally as an architectural feature.

Listed building - a building designated by the Secretary of State (for Culture, Media and Sport) as of special architectural or historic interest. There are three grades - I, II*, and II.

Listed building consent - consent to carry out works to a listed building.


Mansard roof - a roof set back from the building frontage, usually behind a parapet, and rising in two pitches to form an attic space.

Metropolitan Open Land (MOL) - open land of strategic significance, which contributes to the structure or character of the Borough as a whole and provides breaks in the built-up area.

Mullion - a vertical piece of stone or timber dividing a window into sections.


Oriel - a window which is suspended from the face of the building (projecting like a bay, but not extending to the ground).


Pantile - a clay roofing tile with an 'S'-shaped profile.

Parapet - the upper part of a wall, often used to hide roofs and decorated for architectural effect; e.g. crenellated or battlemented in the form of a castle wall.

Party wall - a wall or fence that straddles a boundary between two or more properties or stands entirely on land in one ownership but used to separate two buildings in separate ownership/occupation.

Paviors - small brick-like paving units.

Pediment - a triangular feature of classical buildings surmounting a portico, but often used on a smaller scale over doors and windows, which are then referred to as pedimented. When the upper sloping sides are curved it is called segmental. It may be termed broken or open when either the bottom horizontal or angled upper sides do not meet.

Pergola - an open framework over a walkway or path, which is usually designed to be covered in climbing plants.

Permitted development - development that has been given "blanket permission" by statute and which therefore does not require a planning application to be made to the local authority.

Pilaster - a flattened column used to frame door and window cases and shopfronts.

Planning obligation - a commitment made by a landowner under Section 106 of the Town and Country Planning Act in conjunction with the granting of planning permission, either in the form of an agreement with the local planning authority or as a unilateral undertaking.

Plinth - the base of a column or wall.

Plot ratio - the ratio of the total floorspace in a building (all storeys) to the area of the site on which it stands.

Pointing - the exposed mortar between bricks in a course and between the courses; usually finished flush with the face of the bricks or slightly recessed; colour can be varied for effect.

Porte-cochère - a porch large enough for wheeled vehicles to pass through.

Portico - a grand entrance extending in front of the building line, usually defined by columns and surmounted by a pediment.

PPGs - Planning Policy Guidance Notes published by the Government.


Quoin - a corner of a building defined by contrasting or exaggerated materials.


Reveal - the area of masonry or frame visible between the outer face of a wall and a door or window which is set back from it.

Rooflight - a window fitted flush into a sloping roof. Also known as a "Velux window".

Rustication - stucco or stone blocks with large angled joints.


Sash window - a window that slides vertically on a system of cords and balanced weights.

Section 106 - see planning obligation.

Sett - a small block of hard stone, such as granite, used for paving.

Soffit - the underside of eaves or other projection.

Spandrel - a blank area between arch supports or below a window.

Spatial Development Strategy (SDS) - planning strategy for London, being prepared by the Mayor of London.

Stable block - small square stone or clay pavior traditionally used as flooring in stables and similar buildings.

Stack - the part of the chimney breast visible above the roof.

Statutory period - the time period (usually 8 weeks) within which a local planning authority is expected to make a decision on a planning application. If the period is exceeded, the applicant is entitled to consider the application as being refused and appeal to the Secretary of State against a deemed refusal.

Stock brick - a traditional clay brick commonly used in house construction; often called London stocks because of the frequency of use locally. May be yellow or red in colour.

Strategic guidance - the regional guidance for planning authorities in London, published by the Government. This will be replaced in due course by the Mayor of London's Spatial Development Strategy.

String course - a horizontal band in a wall, usually raised and often moulded.

Stucco - a lime based render applied to the exterior of a building. Often scored to imitate courses of masonry, then called channelled, and sometimes more deeply incised to give the appearance of roughly hewn stone, in which case it is rusticated.

Supplementary Planning Guidance (SPG) - guidance which explains and amplifies the planning policies in the Council's Unitary Development Plan, and provides additional advice to applicants.


Terra cotta - unglazed clay used mainly for wall covering and ornamentation, but can be structural.

Top light - 1) a window in a flat roof or

2) a small pane forming the upper part of a casement window or a shopfront.

Transom - a horizontal glazing bar in a window.

Tree preservation order (TPO) - an Order made by the Council to protect a tree or group of trees. An application must be made to the Council to fell or undertake work to a tree which is subject to a TPO.


Unilateral undertaking - see planning obligation.

Unitary Development Plan (UDP) - the legal plan which sets out the Council's planning policies.

Use classes order - a statute that groups uses into various categories and which specifically states that permission is not required to change from one use to another within the same class.

The main use classes are:

A1 - Shops.
A2 - Financial and professional services.
A3 - Restaurants and cafes.
A4 - Drinking establishments.
A5 - Hot food takeaways.
B1 - General offices, workshops and laboratories.
B2 - Other industrial activities.
B8 - Storage or distribution.
C1 - Hotels and boarding houses.
C2 - Residential institutions.
C3 - Dwelling houses (including up to 6 people sharing).
D1 - Non residential institutional uses.
D2 - Places of assembly and leisure uses.


Venetian - a window composed of three openings or lights within the frame, the central light arched, the two flanking with flat heads.

Voussoir - the shaped bricks or stones over a window forming a head or arch.


Weatherboarding - overlapping timber boards cladding the outside of a building.