Urban Design Dimensions: 5.Functional Dimension

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WHAT IS FUNCTIONAL DIMENSION OF URBAN DESIGN?

Urban design’s functional dimension relates to how places work and how urban designers can make ‘better’ places or increase the potential for them to develop. This dimension of urban design is explained in five parts:

  • movement
  • design of ‘people places’
  • environmental design
  • designing for healthier environments
  • aspects of infrastructure necessary to support contemporary life

MOVEMENT:

Movement is fundamental to understanding how places function. Pedestrian flows through public space where people choose to sit or linger in public space and are related to the life and activity within the space.

Vehicular and Pedestrian Movement:

Car-based movement is pure circulation whereas pedestrian movement is circulation but also permits economic, social and cultural exchange.

nature of pedestrian movement
Nature of Pedestrian Movement
nature of vehicular movement
Nature of Vehicular Movement

Space Syntax:

Space Syntax challenges urban designers to think critically about the relationship between the configuration of space, movement and land-use. It is widely used as an analytic and design tool, and the theories behind its use continue to be developed by Hillier and others.

DESIGNING BETTER ‘PEOPLE PLACES’:

People places are those intended to be used by people, usually through spontaneous, everyday and informal use.

Successful People Places:

road side tea stallSuccessful public spaces are characterised by the presence of people, in an often self-reinforcing process. They typically have animation and vitality that bring people onto the street. Different places are, nonetheless, animated in different ways. Some are louder, busier and more vibrant, animated by people and traffic; others are quieter, perhaps animated by nature – the wind in the trees, changing cloud formations and so forth.

Movement and Activity:

movement and activity
movement and activity in parks

If a space is poorly located within the local movement pattern, it matters little how well it is designed as it is unlikely to ever be well-used unless there are changes in the wider area – either greater density of uses or changes to the movement network that increase connectivity and/or reduce severance (i.e. through better quality connections or by new connections, such as new bridges across rivers, or the removal of obstacles to movement to a site).

If the space is well-located within the local movement system, then upgrading the space and environmental improvements are likely to have a major impact on the density of its use.

Connectivity and Visual Permeability:

Public spaces prioritise sense-of-enclosure within the space over visual permeability into the space. Urban spaces should not be too enclosed. The key quality in terms of the pedestrian use of public spaces is their ‘connectedness’ or, integration.

Activities in Public Space:

As successful places support and facilitate the activities of people, their design should be informed by an awareness of how people use them.

Public spaces should be responsive – that is, designed and managed to serve the needs of their users. Six needs people seek to satisfy in public space.

  1. Relaxation: A sense of psychological comfort is a prerequisite of relaxation, but relaxation is a more developed state of the ‘body and mind at ease’ (Carr et al 1992:98).
  2. comfor and relaxationComfort: The length of time people stay in a public space is a function and an indicator of its comfort.
  3. Passive engagement: The primary form of passive engagement is people-watching. What attracts people is other people, and the life and activity they bring with them. Other forms of passive engagement, as do fountains, public art, commanding views, and activities occurring in public spaces.
  4. Active engagement: Active engagement represents a more direct experience with a place and the people in it i.e. supports social interaction. Successful people places provide opportunities for varying degrees of engagement, and also the potential to disengage or withdraw from contact. Design can create, or inhibit, such opportunities for contact.
  5. Discovery: Representing the desire for new experiences, ‘discovery’ depends on both variety and change for managing and animating public space – by, for example, cultural animation programmes involving lunch-time concerts, art exhibitions, street theatre, live music and festivals, parades, markets, fairs, society events, trade promotions, etc. – across a range of times and venues.
  6. Display: In any public space, we are on display: how we appear, dress and behave in public space not only represents a display but may also be important to our sense of identity and belonging. We may purposefully dress to remain unnoticed or to stand out as different.

The Design of the Edge:

The micro-design and use of successful people places can be considered in terms of the ‘centre’ and the ‘edge’. While something in the middle provides a focus and a sense of visual completeness, this is secondary and what really matters for a successful people place is the design of the edge.

active frontage defining the edge
Active Frontage defining the edge

Active Frontages:

Frontage is how a building addresses the street. Facades can be designed so that buildings metaphorically ‘reach out’ to the street, offering ‘active’ frontage onto public space, adding interest, life and vitality.

Sociability and Privacy:

In urban design terms, privacy is usually defined in terms of selective control of access (to individual or group) and of interaction (especially that which is unwanted). The need for privacy and interaction varies among individuals, with respect to personality, life stage, etc., and across different cultures and societies.

Visual Privacy:

Issues of visual privacy typically relate to the interface between public and private realms and, in particular, the physical and visual permeability between these realms. The requirements of each privacy domain must be enabled while balancing these with opportunities for interaction.

Aural Privacy:

Design strategies can combat noise nuisance. Measures can be taken to prevent or reduce the ‘break out’ of noise, and/or to separate it from noise-sensitive uses, by physical distance, sound insulation and/or through screens and barriers.

Vitality, Mixed and Continuous Use:

A key aspect of creating a lively and well-used public realm is the spatial and temporal concentration of different land uses and activities. Modernist planning, functional zoning approaches had, over time, led to cities dominated by a coarsely gained collage of single-function areas rather than the more fine-grained mixed-use areas of previous eras and have been much criticised.

Jacobs (1961: 155), for example, argued that the vitality of city neighbourhoods depends on the overlapping and interweaving of activities and that understanding cities require dealing with mixtures of uses as the ‘essential phenomena’. She also outlined four conditions indispensable to generating ‘exuberant diversity’ in a city’s streets and districts:

  • The district must serve more than one primary function, and preferably more than two.
  • Most blocks must be short – streets and opportunities to turn corners must be frequent.
  • The district must mingle buildings varying in age and condition.
  • There must be a sufficiently dense concentration of people, for whatever purposes they may be there.
Llewelyn-Davies (2000: 39) identifies the following benefits of mixed-use development:
  • More convenient access to facilities;
  • Minimising travel-to-work congestion;
  • Greater opportunities for social interaction;
  • Socially diverse communities;
  • A greater feeling of safety through more eyes on the street;
  • Greater energy efficiency and more efficient use of space and buildings;
  • More consumer choice of lifestyle, location and building type;
  • Greater urban vitality and street life; &
  • Increased viability of urban facilities and support for small business.

Density:

Indian Bazaar
A typical scenario from an Indian Bazaar

A sufficient density of activity and people has animation and vitality creating and sustaining viable mixed use. Jacobs (1961: 163) considered that density was essential to urban life.

Llewelyn-Davies (2000: 46) suggests a range of benefits from higher development densities:

  • Social – by encouraging positive interaction and diversity; improving the viability of and access to community services, and enabling more and better integrated social housing.
  • Economic – by enhancing the economic viability of development and providing economies of infrastructure (e.g. basement car parking).
  • Transport – by supporting public transport and reducing car travel and parking demand.
  • Environmental – by increasing energy efficiency; decreasing resource consumption; creating less pollution; preserving and helping to fund the maintenance of public open space; and reducing overall demand for development land.

ENVIRONMENTAL DESIGN:

An essential part of urban design is the need to provide comfortable conditions within public spaces. Levels of sunlight, shade, temperature, humidity, rain, snow, wind and noise have an impact upon our experience and use of urban environments.

Microclimate:

Design decisions have an important influence in modifying the microclimate to make spaces more comfortable. Relevant factors at this scale include:

  • Building configuration and its effect on and relationship to buildings and other influences at the site boundary.
  • Positioning of access roads and pedestrian paths, trees and other vegetation, walls, fences, and other obstructions.
  • Orientation of internal and external spaces and facades with respect to the direction of sunlight and shade.
  • Massing and grouping of buildings, including the space between buildings.
  • Wind environment.
  • Positioning of main entrances and other openings acting as transitions between inside and outside conditions.
  • Landscape, planting and water pools/fountains to enhance natural cooling.
  • Environmental noise and pollution (Pitts 1999).

Designing for Sun and Shade:

shaded-walkwaySunlight penetration into urban places and into buildings helps make them more pleasant places. It also encourages outdoor activities; reduces mould growth; improves health by providing the body with vitamin E; encourages plant growth; and provides a cheap, readily available source of energy for passive and active collection.

Two major issues are of concern: orientation & and overshadowing and shading in terms of which the following should be considered:

  • The sun’s position (altitude and azimuth) relative to public spaces and to the principal facades of buildings.
  • Site orientation and slope.
  • Existing obstructions on the site.
  • The potential for overshadowing from obstructions beyond the site boundary.
  • The potential to overshadow nearby buildings and spaces (Pitts 1999).

Air Movement – The Wind Environment:

venturi effect of wind
Designing for wind movement

Wind flow has a substantial effect on the comfort of pedestrians, the environmental conditions within public spaces and around building entrances and the activities that might occur there.

In very humid climates external spaces may need to be designed to encourage a greater through the flow of cooling air, whereas, in arid climates positioning fountains and water features in public spaces help to cool through the evaporation of water vapour.

Lighting:

Natural lighting makes an important contribution to the character and utility of public space. The play of light in urban spaces also has aesthetic dimensions. Frederick (2007: 49) observes how the altitude, angle and colour of daylighting vary with orientation and time of day. In the northern hemisphere, daylight:

  • From north-facing windows is shadowless, diffuse and neutral or slightly greyish most of the day and year.
  • From the east is strongest in the morning, is at low altitude, with soft, long shadows, and is grey-yellow in colour.
  • From the south is dominant from late morning to mid-afternoon, renders colours accurately, and casts strong, crisp shadows.
  • From the west is strongest in the late afternoon and early evening, has a rich gold-orange cast and can penetrate deeply into buildings, but occasionally is overbearing.

The amount of visible sky is crucial to the quality of daylighting.

Although artificial lighting can make a positive contribution to the character and utility of urban spaces, it is often designed only with vehicular traffic in mind and tends to be inefficient in energy use, resulting in light pollution. It has two key functions:

  • Statutory lighting – which provides basic lighting levels, to aid pedestrian way-finding and the secure use of the public realm at night, and the safe passage of vehicles.
  • Amenity lighting – which enhances the street scene through flood, feature and low-level lighting; and gives colour and vitality through signs, shop-lighting and seasonal lighting

DESIGNING HEALTHIER ENVIRONMENTS:

A concern to create environments with better sunlight penetration, ventilation and open space provision, were the driving force behind Modernism’s growth and spread in the first half of the twentieth century, while, in the second half, the built environment was increasingly shaped by concerns about health and safety.

Health as a Strategic Design Concern:

Today, the impact of the built environment on a range of new health-related concerns has again come to the fore, meshing with a wider agenda for healthy cities (Hancock & Duhl, in Barton & Tsourou 2000: 31) encompassing:

  • A clean, safe physical environment of high quality (including housing quality).

    jogging and exercise in parks
    Jogging and exercise in parks
  • An ecosystem that is stable now and sustainable in the long term.
  • A strong, mutually supportive, non-exploitative community.
  • A high degree of participation and control by the public over decisions affecting their lives.
  • The meeting of basic needs for food, water, shelter, income, safety and work.
  • Access to a wide variety of experiences, resources, contact and interaction.
  • A diverse, vital and innovative city economy.
  • The encouragement of connectedness with the past.
  • An urban form that is compatible with and enhances the above.
  • An optimum level of public health services available to all.
  • High levels of positive health and low levels of disease.

The Local Environment:

At the local level, a wide range of detailed technical factors impact on the healthiness of the local built environment. Protection against communicable diseases requires a safe water supply, sanitary sewerage and waste disposal, good drainage of surface water, and provision of facilities for personal hygiene and safe food preparation. Protection against injuries, poisonings and chronic diseases requires adequate structural and fire safety safeguards, low air pollution, safety from harmful materials and from injury on the roads, and through ready access to appropriate emergency services.

There should be the provision of sidewalks, animated streets and enjoyable scenery to promote walking and exercise and pedestrian paths separated from the street.

street-furnitureHealth-Promoting Environments:

Health benefits can be most efficiently achieved through creating ‘health-promotive’ environments in which physical activity is encouraged as a by-product of urban form. They argue that all modes of travel are not equal in this respect – non-motorised modes have clear health consequences, while motorised modes have negative associations.

THE CAPITAL WEB:

The capital web is made up of the above and below ground elements of the city’s infrastructure. Mainly horizontal and also the vertical infrastructure of community centres, churches, mosques, libraries, sports pitches, etc. The major capital web considerations in urban design are the provision of public open space; road and footpath design; parking and servicing; and other infrastructure.

External Public Open Space:

External public open space offers recreational opportunities; wildlife habitats; venues for special events; and the opportunity for the city to breathe. A number of towns and cities have developed sophisticated open space frameworks and green space networks to link open spaces and create ‘green’ corridors through urban areas for recreational purposes and for wildlife. Integration of natural and built environments is a key objective of sustainable development.

Road and Footpath Design:

street section with dedicated lanes
Street section with dedicated lanes

The segregation of pedestrian and vehicular traffic to provide personal safety, often meant pedestrians could only cross busy roads by underground subways or overground foot bridges. In general, the contemporary ethos is to design pedestrian-dominant rather than car-dominant environments: such approaches give priority to pedestrians without banishing the car.

The aim must be to avoid car-dependent environments because this reduces their potential to be sustainable and to increase the potential for walking. Road and footpath design thus need to achieve a set of basic requirements:

  • Maintaining safety and personal security through reducing vehicle speeds, discouraging road and footpath separation and increasing passive surveillance.
  • Increasing permeability and access by all modes of travel but particularly by foot.
  • Encouraging directness by acknowledging and emphasising ‘desire lines’ in development (the most convenient route to where people wish to go).
  • Designing in sympathy with the local context to ensure an attractive development in which clearly defined spaces, landscaping and buildings dominate rather than roads or cars.
  • Increasing legibility through the design of layouts in which the overall structure and local visual references are clear.

Designing For Walking:

There is a difference between ‘necessary’ or utilitarian walking and ‘optional’ or recreational and leisure walking. Many traffic-calming measures enhance walkability, including widening the sidewalks/pavements, thereby reducing the street width.

Designing For Cycles:functional3

The personal health benefits of cycling are greater than those of walking. Cycling provides health and environmental benefits for both the individual and community. To encourage the use of cycles there should be a provision of cycling infrastructures- cycling lane, parking/stands, junctions, signals & signage.

Parking and Services:

parking requirements are a necessity of contemporary living within all environments – whether urban, suburban or rural. Parking needs to be:

  • Sufficient to cater for contemporary needs.
  • Convenient (i.e. located close to destinations) for all users, including those with disabilities.
  • Attractive (e.g. by limiting its visual intrusion – use of landscaping and quality materials can successfully integrate on- and off-street parking).
  • Safe and secure

Where locations are well-served by public transport, required parking standards can be reduced. Charging for parking is one approach to managing demand for parking space.

Car-free housing, where residents contract not to own cars, has been developed in a few locations well-served by public transport.

Contemporary developments also require space for servicing, including business deliveries; waste disposal, storage and collection; recycling points; emergency access; removals; cleaning and maintenance; and utility access.

Infrastructure:

An area’s infrastructure – both that above and that underground – has often been built up over several centuries. Above ground, the capital web incorporates the public space network and landscaping framework; any public transport network and infrastructure; and public facilities (e.g. shops) and services (e.g. schools). Below ground, it incorporates water supply networks; sewage disposal systems; electric grids; gas supply network; telephone networks; cable networks; combined heat and light systems; and underground transit systems.

CONCLUSION:

Discussing the functional dimension of urban design, this chapter reiterates the importance of understanding urban design as a design process. In any design process, there is a danger of narrowly prioritising a particular dimension – aesthetic, functional, technical or economic – and of isolating it from its context and from its contribution to the greater whole. The design must be considered as a totality and in-the-round.

This is a Summary of the Dimensions of Urban Design from the Book “PUBLIC PLACES- URBAN SPACES by Matthew Carmona, Tim Heath, Taner Oc and Steven Tiesdell, Architectural Press

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