Urban Design Glossary

Accessibility

The ability of people to move round an area and to reach places and facilities, including elderly and disabled people, those with young children and those encumbered with luggage or shopping.

Active frontages

Street frontages where there is an active visual engagement between those in the street and those on the ground and upper floors of buildings.

Adaptability

The capacity of a building or space to be changed to respond to changing social, environmental, technological and economic conditions.

Area appraisal

An assessment of an area’s land uses, built and natural environment, and social and physical characteristics. Architecture and planning centre An institution which provides a focus for a range of activities and services (such as discussions, information, exhibitions, collaboration and professional services) relating to architecture and planning.

Brief

This guide refers to site-specific briefs as development briefs. Site-specific briefs are also called a variety of other names, including design briefs, planning briefs and development frameworks.

Building elements

Doors, windows, cornices and other features which contribute to the overall design of a building.

Building envelope

Diagram(s) with dimensions showing the possible site and massing of a building. Building

Building line

The line formed by the frontages of buildings along a street. The building line can be shown on a plan or section.

Character assessment

An area appraisal identifying distinguishing physical features and emphasising historical and cultural associations.

Charrette

An event (ranging from a couple of hours to several days) which brings together a range of people to discuss design issues. A charrette may or may not use techniques of collaborative design. Also known as a design workshop

Co-design

An approach to design attempting to actively involve all stakeholders in the design process to help ensure the result meets their needs and is usable. Focuses on processes and procedures of design and is not a design style. Also known as Collaborative design and Participatory design.

Conservation area character appraisal

A published document defining the special architectural or historic interest which warranted the area being designated.

Context

The setting of a site or area, including factors such as traffic, activities and land uses as well as landscape and built form.

Context (or site and area) appraisal

A detailed analysis of the features of a site or area (including land uses, built and natural environment, and social and physical characteristics) which serves as the basis for an urban design framework, development brief, design guide or other policy or guidance.

Defensible space

Public and semi-public space that is ‘defensible’ in the sense that it is surveyed, demarcated or maintained by somebody. Derived from Oscar Newman’s 1973 study of the same name, and an important concept in securing public safety in urban areas, defensible space is also dependent upon the existence of escape routes and the level of anonymity which can be anticipated by the users of the space.

Density (Gross)

The number of buildings (or some other unit measure) in relation to a given area of land constituting the prevailing density of the locality, including infrastructure such as existing roads, railways, open spaces. Also known as neighbourhood density. Often measured as dwellings per hectare (dph).

Density (Net)

The number of buildings (or some other unit measure) in relation to a specified site (usually defined a within the red line boundary). Also known as site density. Often measured as dwellings per hectare (dph).

Design code

a set of simple, concise, illustrated design requirements that are visual and numerical wherever possible to provide specific, detailed parameters for the physical development of a site or area.

Design Review Panel

A group of people (often built environment professionals) with specialist knowledge, which advises a local authority on the design merits of planning applications or other design issues.

Design guide

A document providing guidance on how development can be carried out in accordance with the design policies of a local authority or other organisation often with a view to retaining local distinctiveness.

Design principle

An expression of one of the basic design ideas at the heart of an urban design framework, design guide, development brief or a development.

Design standards

Specific, usually quantifiable measures of amenity and safety in residential areas.

Design and access statement

A design statement is made by a developer to indicate the design principles on which a development proposal in progress is based. It enables the local authority to give an initial response to the main issues raised by the proposal. It sets out the design principles that the planning applicant has adopted in relation to the site and its wider context.

Design workshop

See ‘charrette’.

Desire line

An imaginary line linking facilities or places which people would intuitively take if free from obstacles and diversions.

Development brief

A document, prepared by a local planning authority, a developer, or jointly, providing guidance on how a site of significant size or sensitivity should be developed. Site-specific briefs are sometimes known as planning briefs, design briefs and development frameworks

Elevation

The facade of a building, or the drawing of a facade.

Enclosure

The use of buildings to create a sense of defined space.

Energy efficiency

The extent to which the use of energy is reduced through the way in which buildings are constructed and arranged on site.

Façade

The principal front of a building, that faces on to a street or open space. Also known as a frontage

Feasibility

The viability of development in relation to economic and market conditions.

Fenestration

The arrangement of windows on a facade.

Figure ground (or Nolli) diagram

A plan showing the relationship between built form and publicly accessible space (including streets) by presenting the former in black and the latter as a white background (or the other way round).

Form

The layout (structure and urban grain), density, scale (height and massing), appearance (materials and details) and landscape of development.

Height

The height of a building can be expressed in terms of a maximum number of floors; a maximum height of parapet or ridge (apex of a roof); a maximum overall height; any of these maximum heights in combination with a maximum number of floors; a ratio of building height to street or space width; height relative to particular landmarks or background buildings; or strategic views.

Human scale

The use within development of elements which relate well in size to an individual human being and their assembly in a way which makes people feel comfortable rather than overwhelmed.

In-curtilage

Within a building’s site boundary, rather than on a public street or space.

Indicative sketch

A drawing of building forms and spaces which is intended to convey the basic elements of a possible design.

Infill (or infilling)

Development within a gap within an otherwise built-up street frontage or urban block.

Landmark

A building or structure that stands out from its background by virtue of height, size or some other aspect of design.

Landscape

The character and appearance of land, including its shape, form, ecology, natural features, colours and elements and the way these components combine. Landscape character can be expressed through landscape appraisal, and maps or plans. In built up or urban areas ‘townscape’ describes the same concept.

Layout

The way buildings, routes and open spaces are placed in relation to each other.

Layout structure

The framework or hierarchy of routes that connect in the local area and at wider scales.

Legibility

The degree to which a place can be easily understood and traversed.

Local distinctiveness

The positive features of a place and its communities which contribute to its special character and sense of place.

Massing

The combined effect of the arrangement, volume and shape of a building or group of buildings. Also called bulk.

Mixed uses

A mix of uses within a building, on a site or within a particular area. ‘Horizontal’ mixed uses are side by side, usually in different buildings. ‘Vertical’ mixed uses are on different floors of the same building.

Modal split

How the total number of journeys in an area or to a destination is split between different means of transport, such as train, bus, car, walking and cycling.

Movement

People and vehicles going to and passing through buildings, places and spaces. The movement network can be shown on plans, by space syntax analysis, by highway designations, by figure ground diagrams, through data on origins and destinations or pedestrian flows, by desire lines, by details of public transport services, by walk bands or by details of cycle routes.

Natural surveillance

The discouragement to wrong-doing by the presence of passers-by or the ability of people to be seen out of surrounding windows. Also known as passive surveillance (or supervision).

Neighbourhood Plan

A form of planning through which professionals and communities collaborate to shape new and existing neighbourhoods.

Node

A place where activity and routes are concentrated often used as a synonym for junction.

Perimeter block

A perimeter block is an urban form in which buildings are surrounded on all sides by public space (often streets) which in turn are defined and (enclosed) by the public fronts of the buildings. A series or network of blocks combine to form a grid.

Permeability

The degree to which an area has a variety of pleasant, convenient and safe routes through it.

Perspective

Illustration showing the view from a particular point as it would be seen by the human eye.

Plot ratio

A measurement of density generally expressed as gross floor area divided by the net site area.

Public art

Permanent or temporary physical works of art visible to the general public, whether part of the building or free-standing: can include sculpture, lighting effects, street furniture, paving, railings and signs.

Public/private interface

The point at which public areas and buildings meet private ones.

Public realm

The parts of a village, town or city (whether publicly or privately owned) that are available, without charge, for everyone to use or see, including streets, squares and parks. 

Scale

The impression of a building when seen in relation to its surroundings, or the size of parts of a building or its details, particularly as experienced in relation to the size of a person. Sometimes it is the total dimensions of a building which give it its sense of scale: at other times it is the size of the elements and the way they are combined. The concept is a difficult and ambiguous one: often the word is used simply as a synonym for ‘size’.

Section

Drawing showing a slice through a building or site.

Settlement pattern

The distinctive way that the roads, paths and buildings are laid out in a particular place.

Sight line

The line of sight from a travelling vehicle or person. Sight lines will help to determine how fast vehicles are likely to move and how safe other road users are likely to be.

Solid-to-void ratio (or void-to-solid ratio)

Void-to-solid ratio in a building façade is defined as the area of the façade covered by openings (windows, doors, arches, etc.) divided by the area of the solid wall

Strategic view

The line of sight from a particular point to an important landmark or skyline. Also known as Key view.

Street furniture

Structures in and adjacent to the highway which contribute to the street scene, such as bus shelters, litter bins, seating, lighting, railings and signs.

Sustainable development

Defined by the Brundtland Commission (1987, and quoted in PPG1) as ‘Development which meets present needs without compromising the ability of future generations to achieve their own needs and aspirations’. The UK’s strategy for sustainable development “A better quality of life” was published in May 1999 and highlights the need for environmental improvement, social justice and economic success to go hand-in-hand.

Tissue study

Comparison of scale and layout of different settlements. This technique makes use of overprinting or tracing maps of successful places over the proposed development site or area, at the same scale. Its gives the designer a clue to the capacity of a place and how it may be structured.

Topography

A description or representation of artificial or natural features on or of the ground.

Urban design

The practice of making places. Urban design involves the design of buildings, groups of buildings, spaces and landscapes, in villages, towns and cities, and the establishment of frameworks and processes which facilitate successful development.

Urban design framework

A document which informs the preparation of development plan policies, or sets out in detail how they are to be implemented in a particular area where there is a need to control, guide and promote change. Area development frameworks are also called a variety of other names, including urban design strategies, area development frameworks, spatial masterplans, and planning and urban design frameworks.

Urban grain

The pattern of the arrangement and size of buildings and their plots in a settlement; and the degree to which an area’s pattern of street-blocks and street junctions is respectively small and frequent, or large and infrequent.

Vernacular

The way in which ordinary buildings were built in a particular place, making use of local styles, techniques and materials and responding to local economic and social conditions.

View

What is visible from a particular point. Compare ‘Vista’.

Vista

An enclosed view, usually a long and narrow one.

Visual clutter

The uncoordinated arrangement of street furniture, signs and other features

Walk (or cycle) band

A line on a map or plan showing the furthest distance that can be walked from a particular point at an average pace in a certain time (usually five or ten minutes).