Lesson 2 town planning concepts

Town & Country PlanningLesson 2

Town Planning Concepts

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Town Planning ConceptsGarden City

Background:Social upheaval in 19th CenturyPhysical repercussion (poor homes, sanitary

problems) on urban formCreation of Model CommunitiesStandards for residential layout and town design

ideal population size related to- provision of services-retention of city identity.

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Introduced by Sir Edenezer Howard (1850-1928)- Book” A Peaceful path to Social Reform -1898”Advocate a Satellite town called a Garden City

comprising:-a) 6000 acresb)32,000 inhabitantsc) A central area of 1,000 acresd)Individual plots 20 feet by 130 feete)Gross density of 30 persons per acre

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There would be 6 boulevards each 120 feet wide extending radially from the centre; these would assist in forming 6 wards which would provide the basis of local government and community services.

“City” would be self sufficient in terms of:a) Employmentb) Possessing its own industryc) Commerced) Shops e) Agricultural production.

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As far as the design goes, Howard wants to make it as little like the overcrowded London of his day as possible, so public parks and private lawns are everywhere. The roads are wide ranging from 120 ft to 420 ft for the Grand Avenue, and they are radial rather than linear. Commercial, industrial, residential and public uses are clearly differentiated from each other spatially.

The overall goal is to combine the traditional countryside with the traditional town. The 2 “magnets” of Town and Country that have in the past pulled people in either direction will, in the future be synthesized into one “ Town –Country magnet”.

Howard suggested that a house-owner’s association owns all the land of the city and leases it out to residents. The financial linchpin of the plan is the fact that all of the land is purchased upfront so that the increase in property values generated by the growth will be captured by the community itself. He also assumes that if everything is planned rationally from the beginning, the costly process of retrofitting old infrastructure for new technology can be avoided. The flaw is the proposal is Howard has little respect for limits.

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Garden City Howard envisaged a whole molecular infrastructure

of garden cities clustering around a central city of about 50,000 population.

A great deal of criticism has been levelled at Howard’s plans as being unrealistic in their adherence to geometric proportion, but he presented his design of concentric circles of varying land use as a universal rather than as a particular mode.

First Garden City was Letchworth in Hertfordshire .

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THE THREE MAGNETS COUNTRY TOWN Advantages:Disadvantages - fresh air-Traffic congestion - cheaper land

-High population - close to nature Density CITY CENTRE 50,000 population

TOWN-COUNTRY 6000 acres

32,000 population Central Area- 1,000 acres

Gross Density- 30 ppa 6 Boulevards

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The Linear City: (Don Arturo Soria y Mata- 1882)- A town for 30,000 people based upon the

principal transport route which is 100 meter wide of infinite length depending upon urban growth.

- All services channelled along the street- Other community facilities group at regular

intervals - Residential area is limited to 200 meter either

side beyond which would lie the Countryside.

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Town Planning ConceptsLinear City

200 meter Road 100 meter

Community facilities

Country Side

500 meter Residential Areas

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Linear City

Advantages:1. A simple economical form of traffic segregation2. A pattern of movement and location

comprehensible to the average citizen3. The town centre grows in proportion to the

demands of residential and industrial expansion4. Subsequent possibility of expansion to absorb a

larger population.

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Linear City

Critics:1.Accessibility to central area is impaired2.Separation of arterial and local traffic is

exceptionally difficult to achieve3.Services have to be provided over a longer

distance and are therefore more expensive.

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Radburn SuperblockBandar Botanic in Klang-use this Planning Concept

Characteristics-a) Encourage pedestrian accessibility

- Low traffic volume in the neighbourhoodb) Open space linked the residential areasc) Houses built around cul-de-sac which are

connected to open spaced) Houses are segregated for main roadse) Pedestrian paths and walkways linked the

houses to primary school and local centre

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-Population Size: 25,000Into 3 neighbourhoods of around 8,000 each- Pedestrian –traffic segregationBy means of:-

- foot paths-under passes-bridges-residential superblocks around a backbone of parkland.

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Cul-de-sac

Open Space Local Centre, school

Pedestrian Link

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Neighbourhood UnitSubang Jaya

-Clarence Perry (1910)- A scheme of arrangement for the family life

community- All residents were within convenient access to:– primary school– Open space– Local retail centre

- Planned according to its terrain and structure.

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6 Principles of Neighbourhood Designa) Size of neighbourhood unit related to the catchment area

of a primary schoolb) No through traffic- residential area bounded on all sides by

arterial roadsc) ample parks and play areasd) A neighbourhood centre containing school, local centre and

other servicese) A hierarchy of roads/ streets (to promote road safety,

pedestrian safety, conserve residential environment)f) District shops located on the periphery thus serving 4

neighbourhood unit.

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Provide acc Access to Area

0-15 minutes walking time ¼ mile

SIZE: 160 Acres Note: No through Traffic

10 Local

centre

Arterial Roads

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District Centre (Provide services of higher order)

4 local centre to support District Centre

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Green BeltsAs a restriction on urban growth the notion of a green belt has

always occupied an important function in planning theory.1. It prevents the loss of a town’s identity2. It ensures the economic use of urban land and facilities3. It prevents ribbon development4. It ensures that adequate recreational facilities are within

everyone’s reach5. It combats air pollution6. It preserves the environment7. It prevents the erosion of agriculture land.

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Green Belts

A green belt is a policy and land use designation used in land use planning to retain areas of largely underdeveloped, wild or agricultural land surrounding or neighbouring urban areas. A green belt is basically an invisible line that goes around a certain area, stopping people from building there so that some of the wild and agriculture land can be saved.

In those countries which have green belt policy, development in green belts is heavily restricted.

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Green Belts

The stated objectives of green belt policy are:-a) Protect natural or semi natural environments.b)Improve air quality within urban areasc) Ensure that urban dwellers have access to

countryside with consequent educational and recreational opportunities

d)Protect the unique character of rural communities which might otherwise be absorbed by expanding suburbs.

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Green BeltsThe effectiveness of green belts differ depending on

location and country. Criticism against it is that a green belt is created by residents to preserve the status quo of those living within the zone and especially the advantage of landlords who profit from a scarcity of housing. Another criticism is that since green belts does not extend indefinitely outside a city, it might spur the growth of areas much further away from the city core than if it had not existed thereby increasing urban sprawl.

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Green Belts

While the green belt policy is one of the most simple of all planning concepts, its implementation is far less straightforward the approval of unfortunate development, the pressures for housing land, the conflict between recreation and agriculture, changing central and local government objectives, and the lack of positive landscape treatment have all combined to erode the effectiveness of the green belt policy.

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Hierarchy of Urban Centres Central Place Theory- Walter Christaller

The assessment of shopping demand and decisions regarding retail location have their roots firmly planted in Central Place Theory (CPT)

The theory was developed and applied to retail service activity in the 1930s by Walter Christaller and Losch. They extended the notion of centrality, defining and detailing the importance of central places with reference to a series of complementary regions, examining the trade areas or hinterlands for a range of different goods and services.

From their analysis they ascertained that different types of business have different conditions of entry, which they described as thresholds, some requiring larger minimum trade areas or support population than others.

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Consumers spent varying amounts on different goods and services and purchased them at varying intervals.

From this, they postulated a clearly identifiable hierarchy of central places.

Christaller constructed his hierarchy from the strongest or highest order centre downwards, requiring all his lower order centres to take account of them in determining their own location. Losch built his hierarchy from the lowest order goods upwards, allowing a certain degree of manipulation of the location of centres to obtain an optimum hierarchy taking account of every level.

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The distribution of centralized services accounts for the spacing, size and function pattern of urban centres. Centralized service centres would be distributed regularly within a systematic pattern.

Market areas or spheres of influence would take the form of a hexagonal mesh. This would avoid either certain areas not being served or other areas being served by overlapping hinterlands consequences of a pattern of circular market areas.

The main function of each town would be to supply goods and services to the countryside- town and country being interdependent.

Towns with the lowest level of specialization would be evenly spaced and surrounded by their hexagonally shape market areas.

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For each group of 6 towns there would be a larger city with more specialized functions which would be located an equal distance from other cities with the same degree of specialization.

Such cities would have larger hexagonal hinterlands for their own specialized services. Even larger and more specialized settlements would have larger market areas and be situated at an equal distance from each other.

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The lowest ranked centres were likely to be located 7km apart. Settlements of the next highest level would serve 3 times the area and 3 times the population. Thus they would be situated 12 km apart (square root 3 X 7). Similarly the market areas of centres of the next rank would be 3 times larger. Towns without the hierarchy would grow as a result of an increase in production of goods and services to satisfy an increased demand from a growing population within their zones of influence but generally they would remain within their rank and the rule of 3 would persist.

The hierarchy would be modified by long distance trade, by transport routes and by administrative functions. Towns influenced by these factors would have larger populations than their local market would imply.

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Hierarchy of Urban CentresFunctions of Regional Centre:This generally supports a population in excess of 300,000

and contains may specialist services and a full range of department stores. It is predicted that such centres are likely to experience a decline in trade owing to increased car ownership and worsening congestion, but their severity of the decline will vary from centre to centre. Where the whole spectrum of alternative centres is available the regional centre receives approximately 15% of total consumers’ retail expenditure, most of which is spent on durable goods.

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Hierarchy of Urban Centres

Functions of District Centre:These centres cater for a catchment area of about

50,000 sometimes less and normally include a variety store such as Woolworths and supermarkets like Tesco. There are few, if any, specialist services and can be found in suburbs of large cities like Kuala Lumpur. The account for about 25% of the total consumer expenditure and very much more if other levels are not present.

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Hierarchy of Urban Centres

Functions of Local Service Centre:This consists of a few shops supplying a

population of up to 2000. They account for up to 20 per cent of retail expenditure.

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Concentric Zone Theory (E.W Burgess)

• Concentric zone theory emerged from the work of E.W. Burgess on Chicago city in the year 1900.

• He suggested that the urban land use structure of Chicago city has characteristics of concentric circle.

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Concentric Zone Theory

Concentric circle can be distinguished into five zones, which are:

a) Central Business District (CBD)b) Transitional Zonec) Low Income Housingd) High Income Housinge) Commuter Zone

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Concentric Zone Theorya) Central Business District (CBD)The CBD is a concentration of all the main

businesses, offices and retails outlets in the city and is frequently the oldest part of it.

The pattern is not static but changes in the sense that as the CBD expands and the city grows, the core engulfs areas of poor housing for redevelopment and the lower income groups living there are forced to move further out.

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b. Transitional ZoneSurrounding the CBD is usually a ring of

residential property which in the past provided accommodation for those working in the CBD but with the growth of suburbia, has become rundown and now houses the poorest sections of the community.

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c. Low Income HousingSurrounding this first ring is another, comprising

better quality and newer houses which provide homes for middle income workers.

d. High Income HousingFurther out are more expensive houses which

form the commuter belt and are where the highest income earners live.

CBD Inner City Inner Suburbs Outer Suburbs Industry

Tallest Buildings

Shops

Entertainment

High Land Values

High Density

Terraced Housing

Some old factories

Semi-detached housing

Some greenery

Gardens

Low density housing

Large detached houses

Garages

Gardens

Rural-urban fringe

Industry

Retail Units

Car parking space

Examples:

Market Hill East Street Green Leys Burleigh Hill Rainbow

URBAN LAND-USE TRANSECT IN ST IVES

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There is a continual pressure for each successive circle to move outwards over time and for land houses to pass from higher to lower income groups as the city grows (This is known as filtering)

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The Concentric Zone Theory Legend:1.Central Business District (CBD)2.Transitional Zone 3.Low Income Housing 4.High Income Housing5. Commuter Zone

Ribbon Development

Ribbon development means building houses along the routes of communications radiating from a human settlement. Such development generated great concern in the United Kingdom during the 1920s and the 1930s, as well as in numerous other countries.

Increasing motor car ownership meant that houses could be sold even if remote from shops and other services. It was attractive to developers because they did not have to waste money or plot space constructing roads.

The practice became seen as inefficient use of resources and a precursor to urban sprawl, meaning that a key aim for the United Kingdom's post-War planning system was to halt ribbon development. It led to the introduction of green belt policies.

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http://en.wikipedia.org/wiki/United_Kingdom

http://en.wikipedia.org/wiki/Motor_car

http://en.wikipedia.org/wiki/Urban_sprawl

http://en.wikipedia.org/wiki/Town_and_Country_Planning_in_the_United_Kingdom

http://en.wikipedia.org/wiki/Green_belt

Ribbon Development

Intensive uses of production, residence, commerce and services are located along on either side of the lines and specifically form dense nodes at transport stops.

Less intensive uses are located in parallel bands of space outside the compact strips of development.

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Ribbon DevelopmentRural land is immediately beyond the less dense bands and in close

proximity to all development which is relatively shallow.Overall ribbon development in city is compact but has no central core.There would be relatively equal access to services, jobs and open land

though areas between transport stops are likely to be less well served than areas around a transport node.

The public transport system would be efficient as the city form follows its linear nature in ribbon development.

There would be a reasonably good mixture of uses in the band of intensive users and around transport stops and a considerable variety of housing is possible ranging from high density low rise along the linear centre and around transport stops to single family homes at the city’s edge to the open country.

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Ribbon DevelopmentThe resulting towns and cities are often difficult to serve

efficiently. Often the first problems noticed by residents is traffic congestion as people compete to move along the narrow urban corridor while ever more people join in the ribbon further along the corridor.

Urban consolidation is often a solution to encourage growth towards a more compact urban form.

Ribbon development can also be compared with a linear village that grew along a transportation route, not as a part of a city’s expansion.

It is not favoured because it did not maximize infrastructure.

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Discourage of Ribbon Development

1) Use of green belt to check the unrestricted sprawl/ribbon development of large built up areas.

2) All developments should follow strictly to the approved local plans on land use, density and plot ratio.

3) Approval for construction of new buildings would have to be well designed, appropriate in size and form to the neighbouring buildings, and the whole development should integrate with its surroundings.

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Example of Ribbon Development

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Polish village Dubiny, example of an old ribbon village

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Lesson 2 town planning concepts

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Transcript of Lesson 2 town planning concepts