Mazlin - Small Urban Neighbour Hoods

13th International Conference On Humane Habitat (ICHH), Mumbai, India, 28-30 January 2011

Tessellation planning and the small neighbourhood as an appropriate scale for social amenities and engineering infrastructure to meet urban needs

Mazlin Ghazali1 and Anniz Bajunid2

1Arkitek M. Ghazali,2Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA Malaysia

[email protected]

Introduction

Urban society often lack a sense of community found in traditional rural areas. Tessellation planning seeks to create small neighbourhoods in urban areas that are more conducive to the creation of social bonds between neighbours.

Such small neighbourhoods - of about 5 to 22 houses clustered around a courtyard - opens the way for “village” scale solutions and technology to the provision of infrastructure and social amenities. In particular, this layout was proposed as an alternative to terrace houses which are the most common form of housing in Malaysia.

The small neighbourhoods are designed using the tessellation technique: buildings are arranged around courtyards in an interlocking arrangement of cul-de-sacs such that each building lot would face two or three cul-de-sacs. The buildings can be divided into 2,3,4 or 6 thus creating duplex, triplex, quadruplex or sextuplex units.

Tessellation planning creates cul-de-sac neighbourhoods that can achieve the same densities as terrace housing. Yet there are fewer roads, shorter lengths of services like storm water drains and sewer lines, and land is used more efficiently. Every house faces a small park which serves as a social focus to the small neighbourhood, easily accessible and most valuable to small children, the old and disabled. The road system eliminates through traffic, slows down vehicular speed and minimizes traffic danger. The many “eyes on the streets” overlooking the courtyard and the perception of it as a semi-private area reduces the danger from crime and “stranger danger”.

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Tessellation Planning and the Small Neighbourhood as an Appropriate Scale for Social Amenities and Engineering Infrastructure to Meet Urban Needs - Mazlin Ghazali and Anniz Bajunid


The neighbourhood unit concept, first put forward by Clarence Perry, envisaged the neighbourhood in a city as an analogue of the small town. In contrast, the idea of small neighbourhood gives more emphasis to neighbours being able to recognize, get to know, interact and form social groups with each other. This is only possible among small groups of people, perhaps at maximum about 150 people as anthropologist Dunbar suggests. However, the small neighbourhoods (less than 150 persons) can combine to create bigger neighbourhoods including the Neighbourhood Unit that Clarence Perry envisaged (1500 people).

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In modern society governments have taken over the responsibility of providing many of the infrastructural and social requirements of its citizens. Some of these responsibilities have been delegated to local government at State or Municipal levels. Many others can be tackled at the level of the individual or his family.

In many cases, technology provides economies of scale, but sometimes not. There may be many problems that are best tackled at the level of the level of the small neighbourhood made up of a small group of houses. This paper looks at some small scale solutions that can be adopted for small neighbourhoods, namely: security, recreation, greenery, drainage, sewerage and solid waste disposal.

Living amongst strangers, public safety is important. At national level, governments maintain a police force; individuals maintain the safety of their families and their homes with security locks and grills. Small neighbourhoods can employ the principles of "Defensible Space" with clear delineation of boundaries and entry points that encourage residents to assume ownership of the space just outside their homes and for non-residents to perceive it as a semi private space. With many eyes overlooking the communal courtyard, the best security measure is a good neighbour.

Whilst adults and older children are mobile and have a wider area to socialize, play and relax, generally small children are restricted to their homes unless accompanied by their parents. Children’s in cities nowadays lack opportunities for independent outdoor play which is an important component of growing up. The communal courtyards in the small neighbourhoods, if perceived by parents to be safe from traffic and strangers, are suitable for small children to play with their friends overlooked by their parents and neighbours. It would also be easily accessible to other less mobile members of society – the old, infirm and disabled.

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Parks in the city also provide the main link with nature for city dwellers and have been described as being part of the “green infrastructure” where neighbourhood parks are linked by river and other nature corridors to town parks and the countryside. For most people, trees form the primary form of contact with nature – they relieve stress and can improve concentration. Through shading and transpiration, they can reduce ambient outdoor temperature and mitigate the “heat-island effect. Pocket parks in the courtyards bring this green infrastructure to the front doors of homes.

Environment-friendly drainage involves retaining water to moderate run-off during peak rainfall. In wet equatorial Malaysia, 3 to 5% of land to be developed is set aside a retention pond. Otherwise expensive underground water detention tanks have to be built. In small neighbourhoods the generous garden areas in the house compound as well as the pocket park area of the courtyards can be designed to retain water. In addition, the centralized neighbourhood unit park can also be designed to retain water.

This system of small "dry ponds" together with a simple system to harvest rain-water from the roof gutters for outdoor washing and gardening, water discharge during heavy rainfall can be moderated, greatly reducing the need for a retention pond.

Treatment of sewerage can be done at the level of individual houses as in the septic tank or centrally at municipal sewerage treatment plants. In between these two scales are also small sewerage treatment plants suitable for just about any number of dwellings. The septic tank is the cheapest way of of treating effluent at locations where the environment can cope with the effluent discharge. However, in dense city areas, the ambient environment cannot cope with this quality of discharge. On the other hand, centralized systems are expensive to build and maintain.

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Small neighbourhoods can take advantage of cluster systems where septic tanks are still used for primary treatment, but discharge their liquid effluents into small diameter pipes which then flow, by gravity or pump, to a centralized facility for secondary treatment before the effluent is finally discharged into the environment. The small parks in the courtyard can easily accommodate communal septic tanks below ground. Effluent is discharged by pipes of less than 40mm diameter to another location for secondary treatment before final discharge to a more suitable receiving environment.

Measures taken at the level of small neighbourhoods can reduce the volume of waste disposal, and therefore reduce the cost of volume as well as transport to landfills. Segregated bins shared by each small neighbourhood can increase the percentage of recycling. Communal composting can process garden waste. Grinding kitchen waste can half the amount of organic waste. The volume of waste that needs to transported out to landfills can be halved.

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Many countries like Malaysia have adopted the recommendation put forward by Clarence Perry and others to provide 10% of a town plan to be set aside as green open areas. In Tessellation Planning layouts, the green is redistributed with pocket park areas that can also be used to meet infrastructure needs for storm water retention and primary sewerage treatment, and can also be designed to cater for the needs of solid waste recycling, children’s outdoor play and recreation, and public security.

In countries where this green area is not mandatory, the usefulness of the pocket parks to meet many “soft” and “hard” infrastructural needs makes them easier to justify in economic terms.

Background Many look upon cities out the overcrowded slums, poverty and pollution1. Yet, from even before the industrial era, cities have grown as more and more people moved from rural to urban areas in search of greater opportunities and quality of life. However, whilst pre-industrial cities were limited in size; with industrialization, medieval cities began to tear down their walls and grew exponentially. This trend continues until today and is expected to continue.

Nowadays urbanization is not considered to be wholly negative2. The World Bank’s World Development Report in 20093 suggests that pessimism over the future of huge cities is wildly overdone. The bank argues that third-world cities grow so big and so fast precisely because they generate vast economic advantages and that these gains may be increasing.

The expansion of megacities appear to have moderated; growth has spilled over to second tier cities and towns where the medium density pattern of development found in Malaysian new towns and city outskirts found in Malaysia becomes more significant. For example, nearly 35 Indian cities have a population exceeding 1.0 million and a rapidly growing

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consumer market with rising incomes and the Indian government is keen to encourage economic expansion there. Economic growth in these smaller cities is increasingly driven by a manufacturing boom and the expansion of business services outsourcing industries.4

Creating small neighbourhoods in Malaysian urban areas

In rural areas, small towns and pre-industrialized cities, social relationships were based on personal stable bonds of friendship and kinship spanning generations such that people had a sense of belonging to the entire group and possessed a sense of community. By contrast modern society in industrial cities and post-industrial urban areas is characterized by impersonal and specialized relationships, with little long-term commitment to the group or consensus in values. In these societies even neighbours are strangers to each other with little in common.

Ferdinand Tonnies in 1887 contrasted “Gemeinschaft” against “Gesselschaft” associations. The first is characteristic of stable rural traditional communities where are regulated by common mores, or beliefs about the appropriate behavior and responsibility of members of the association than by self interest. By contrast, “Gesellschaft” society is maintained through individuals acting in their own self interest. A modern business is a good example of “Gesellschaft”, the workers, managers, and owners may have very little in terms of shared orientations or beliefs, they may not care deeply for the product they are making, but it is in all their self interest to come to work to make money, and thus the business continues.

Unlike “Gemeinschaften”, “Gesellschaften” emphasize secondary relationships rather than familial or community ties, and there is generally less individual loyalty to society. Social cohesion in “Gesellschaften” typically derives from a more elaborate division of labor. Such societies are considered more susceptible to class conflict as well as racial and ethnic conflicts 5.

An important aspect of this view is that in the transition from pre-industrial cities, the sense of community has been lost.

Terrace Housing

The terrace house-type was introduced into Malaysia by the British. This house-type has the advantages of being considered the densest form of landed property development (10 to 16 units an acre). The typical lot varies from 16’ x 50’ to 24’ x 100’, but the most common lots now are between 20’ x 65’ and 22’ x 70’. The terrace house type has proved itself sufficiently flexible as to be able to cater for low end, medium cost as well as high priced housing.

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It also lends itself to batch construction methods to build large numbers of housing more cheaply. It has also proved itself to be a desirable upgrade from traditional kampong houses. These advantages have made the terrace houses the most common form of housing in Malaysia.

However, the ubiquitous terrace house plan has been designed and re-designed many times, always within the same restrictive framework without much scope for innovation. The layout also has become stereotyped. In the typical housing estate, the terrace houses are lined up along grid-lines with 40’ service roads in front with much smaller back lanes and side lanes. Communal areas for schools, civic and religions building as well as open areas for children playgrounds and parks are also provided. Despite the infrastructure provided, the design of many housing estates does really meet the practical needs of the average resident. Apart from the aesthetic boredom of rows and rows of houses, among the drawbacks of the terrace house layout is the lack of public security and a genuine sense of community. However, terrace house neighbourhoods have been criticised as being monotonous and hot concrete jungle, lacking a real sense of community6.

Tessellation Planning is about trying to overcome this drawback of modern urban life in terrace housing.

Alternatives to Terrace Housing

Developers, planners and architects have come up with several alternatives to the drawbacks of linear planning. In trying to improve the monotony of housing in rows, planners have devised various strategies:

Strata-title development Groups of houses share ownership of the communal facilities allowing greater freedom in designing the access route and common facilities allowing high densities. The Desa Park Homes development in Kuala Lumpur is an example of this type of approach. It is able to achieve densities as good conventional terrace house layouts. However, strata- titles are considered not as valuable as land titles.

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Organic Layouts Following the trend from more developed countries, Malaysian planners have devised ‘organic’ layouts where winding roads and occasional cul-de-sacs break the boredom of the rectilinear grid, but density is sacrificed. A Guthrie development at Bukit Jelutong outside Kuala Lumpur is an example of this trend. However, the houses there achieve low densities and consequently cost significantly more than conventional terrace houses.

Similarly, the cluster approach can produce interesting outcomes but, in most cases, loses out on efficiency. Circular clustering of houses at Brondby near Copenhagen in Denmark Shows a wide expanse of green area between the clusters.

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From America has come a new trend against suburban sprawl. The Neo-Traditional Development seeks to rediscover the vitality found in small towns by re-introducing the rectilinear grid, often overlaid with diagonal streets to link focal points.

What most of these efforts require is additional resources. More land, more infrastructure, more money and you will have a better environment. The main aim in developing another alternative to terrace housing is to find a way to improve the design of housing but without necessarily having to spend more.

The Tessellation Planning Alternative

The geometrical technique of tessellation is applied to the design of housing layouts so as to achieve small, intimate neighbourhoods7. In an example of a tessellation layout - groups of 5 to 16 houses are arrayed around a looping road, such that each house faces a kind of a courtyard. These small neighbourhoods have clear boundaries, limited access and what can be easily perceived to be a semi-public communal space. This cluster form of layout can

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encourage a community lifestyle - like that found in traditional villages - in an urban or suburban context. The aim is to re-create the traditional “kampong” in an urban context.

Although tessellation planning can be applied to create alternatives to other buildings like detached houses, semi detached houses, shop houses, low rise and high rise apartments, these alternatives are outside the scope of this paper8.

Small community solutions to urban needs and problems

In developing the Tessellation Planning concept we first looked at how the small neighbourhood is a very suitable scale to solve the urban need of for safety and recreation, especially for small children. A strong sense of community amongst neighbours also makes it easier to adopt small "village" scale solutions in urbanized areas.

Now encouraged by this conference, this paper will start to look at how the resources and cooperative spirit shared by small groups can help solve some of the basic needs of urban life. These needs include the “soft infrastructural facilities” for recreational and communal purposes, and also “hard” infrastructure like roads, drains, sewerage, and the supporting amenities and services like security and solid waste disposal. It will present a set of possible alternatives at concept stage so that these can be developed in detail and can then be compared to conventional solutions at a later stage,

Tessellation planning

Cul-de-sacs are popular: they are perceived as being safer, more exclusive and neighbourly. According to one study, between the ‘grid’, ‘loops’ and cul-de-sacs, the latter were the most popular9. However, in developing countries like Malaysia, only the very rich can afford to live in quarter-acre single-family houses located in a cul-de-sac. The Tessellation concept was a response to the questions of how can the cul-de-sac be made affordable for more people.

First, buildings are arranged around a courtyard to create a cul-de-sac. However, the cul-de-sac is made bigger so as to fit in a public green area in the middle in order to meet local

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planning regulations that require 10% of any residential development to be open space. Then an interlocking arrangement of cul-de-sacs is created such that each building lot would face two or three cul-de-sacs. If the buildings in this layout were detached houses, they would be priced in the top range of the market. But instead, the buildings are divided into 2, 3, 4 or 6, creating duplex, triplex, quadruplex or sextuplex units.

As the buildings are divided, the land area and the built-up area become smaller; the number of units in the layout and the density of the development go up to rival that obtained in terrace house developments. In this way, the housing units become less expensive. Yet each house still retains a public access. The size and shape of the external environment are not changed – only now more units share it.

Since houses are built around a small park with plentiful shady trees, this communal garden is easily accessible to all in the cul-de-sac, allowing it to act as a social focus that can interaction and encourage neighbourly spirit.

The short winding roads put a stop to speeding traffic, and certain to dissuade snatch thieves on motorcycles - thereby becoming safer for children, pedestrians and cyclists.

Apart from the social advantages, a study has shown that compared to the terrace house layout, the Tessellation layout uses land efficiently and offers savings in the cost of infrastructure10.

Tessellation

The Tessellation layout described above may be said to be inspired from the structure of beehives, but it is also based on a branch of mathematics. In geometry, to tessellate means to cover a plane with a pattern without gaps or overlap. Regular tessellations occur when the

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tiles are regular polygons and they are the simplest form. Tiling is the most common form of tessellation.

Artists and craftsmen from cultures spanning the globe and throughout history have used tessellations as a tool to create visual effects on surfaces. As shown by this example from Spain in the 15th century shows how intricate and complex designs can be built-up by tesselating simple tile patterns.

In Tessellation planning, the creative power of tessellation is applied to town planning, where the colours are not merely decorative but represent functional space.

Re thinking the Neighbourhood concept

Clarence Perry’s ‘Neighbourhood Unit’ population of about 3,000 to 10,000 residents would have its own elementary (primary) school of about 1000-1600 children11. The school, along with other communal facilities like a hall, library and religious building would be centrally

1 Mike Davis Planet of Slums 20062 “Cities and growth - lump together and like it, The Economist print edition, Nov 6th 20083 World Development Report 2009, World Bank4 An Hodgson,” The rise of second-tier cities in India”, Euromonitor.com. 2007, http://www.euromonitor.com/The_rise_of_second_tier_cities_in_India ,retrieved 13th january, 20115 Diana Kendall, Sociology in Our Times, pp 123 and 492, 6 Encyclopedia of Malaysia Vol 5 Architecture, Chen Voon Fee, editor, 2005 Editions Didier Millet7 Davis, M. P., Ghazali, M., & Nordin, N. A. (2006). Thermal Comfort Honeycomb Housing: The Affordable Alternative to Terrace Housing. Serdang: Institute of Advanced Studies, UPM.8 For information on these other forms of Tessellation Planning: detached and semi-detached houses - see http://pasirputehmosaic.blogspot.com/2007/06/faux-bungalows.html; shop houses – see http://kotapuri.blogspot.com/ ; low rise apartments – see http://tessellarhoneycomb.blogspot.com/2008/05/point-block-low-rise-low-cost.html9 Eran Ben-Joseph (1995), “Livability and Safety of Suburban Street Patterns: a Comparative Study”, Working Paper 641, Berkeley, CA: University of California10 Ghazali, M., Sia, C. T., Chan, E., Foo, E., & Davis, M. P. (2005). Honeycomb Housing: Reducing the Cost of Land and Infrastructure in Housing Developments. Kuala Lumpur.

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http://tessellarhoneycomb.blogspot.com/2008/05/point-block-low-rise-low-cost.html

http://kotapuri.blogspot.com/

http://pasirputehmosaic.blogspot.com/2007/06/faux-bungalows.html

http://www.euromonitor.com/The_rise_of_second_tier_cities_in_India


located. The neighbourhood would be ringed by arterial roads. The arterial road was designed to discourage through traffic into the residential neighbourhood and to also give a distinct boundary to the neighbourhood. The shopping area would be at the periphery of the neighbourhood, along the arterial road. There should be a system of small parks and recreation areas to serve the children and youth. He suggested 10% of the total area to be a reasonably good provision. The roads within the neighbourhood would be the small local roads in front of the houses and collector roads that join the local roads to the arterial roads.

The neighbourhood of Radburn serves as a good example of neighbourhood designed

There has been confusion with both the words ‘neighbourhood’ and ‘community’ having different meanings of a social and physical nature. Developers routinely use the word ‘community’ to mean housing estate. Perry introduced the concept of neighbourhood unit in the 1920’s in New York with a list of physical planning characteristics that could encourage city folk to develop a common sense of belonging, a ‘neighbourhood’. But does it really work?

Neighbourhood - social rather than physical

A neighbourhood should not be understood in terms of a list of ingredients in a recipe, but rather whether residents actually feel the sense belonging to a neighbourhood and act accordingly to that perception. To measure these aspects, we need to look at the quantity and quality of social interaction, mutual cooperation between neighbours, positive feelings towards neighbours (without necessarily having social contact), influence, membership and sense of place and belonging.

11 Perry, C. A. (1929). The Neighborhood Unit. In T. Adams (Ed.), Neighborhood and Community Planning (Vol. Vol. VII). New York: The Regional Survey of New York and Its Environs.

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Tessellation planning is premised on the hypothesis that residents who live in small neighbourhoods are more likely to recognise, get to know, interact and form social groups than those who live in bigger neighbourhoods. Evolutionary anthropologist Robin Dunbar has a famous theory that the number of people with whom one can maintain a close relationship is limited to 150 by the size of the neo-cortex, the part of the brain used for conscious thought and language12. This is supported by observation on the sizes of stable communities across cultures. From example, from the perspective Islam, that a neighbourhood should comprise not more than 40 houses, which is equivalent to a ‘cul-de-sac neighbourhood’13.

An alternative Concept of Neighbourhood

Tessellation planning adopts a hierarchical concept of neighbourhood. A family may belong simultaneously to a ‘courtyard neighbourhood’ (less than16 houses), a ‘cul-de-sac neighbourhood’ (less than 42 houses), a ‘block neighbourhood’ (less than 250) and a ‘town community’ of around 1500 houses. The latter is what corresponds most closely to Perry’s neighbourhood unit.

However, arguably, it is at the level of the ‘courtyard neighbourhood’ that the sense of neighbourhood would be strongest; a cluster of 16 houses with a population of only 80 is a setting where residents can easily relate to each other.

Small scale solutions

Many of the needs of the urban population can best met with technological solutions that benefit from economies of scale that is best tackled at the national or regional, or municipal level. Many others can be tackled at the level of the individual or his family. However, there could also be many problems that are best tackled at the level of the level of the small neighbourhood made up of a small group of houses.

Whereas common facilities provided at the level of the city, town or neighbourhood unit level involve thousands of people or more, their provision and maintenance have to involve formal

12 Dunbar, Robin, Grooming, Gossip, and the Evolution of Language, 1998.13 Dr. Asiah Abdul Rahim, “Housing from the Islamic Perspective”, 2008

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administrative entities, usually the municipal authorities or local government, and would normally involve taxation and bureaucratic apparatus, creating a separation between user and provider.

However, common facilities provided at the level of the small neighbourhood can be sustained on less formal arrangements, and can be expected to be more responsive because the users and providers would be the same people.

Still it is believed that the best solutions may require a combination of action at the level of the individual, small community and local government.

The following section will present some of these possible solutions.

Security

Living amongst strangers, security is an important aspect of urban living. Public security is provided by the police service and individuals take precautions, like installing bolted doors, grills or alarms to their homes, to ensure the safety of their family.

Gated communities are an intermediate solution where the residents of that community share the cost of employing private security guards. However, gated communities tend to cater for the wealthy who can afford it.

Environment and Crime

Crime is no doubt mainly linked to social factors, but there is a body of work that has found clear links between crime and the environment where crimes happen. This is the ‘Defensible Space’ concept which evolved some 40 years ago when American architect Oscar Newman was witness to the terminal decline of the newly constructed, 3000-unit, public housing high-rise development, Pruitt-Igoe.

The project was designed by eminent architects and was hailed as a shining example of Modern Architecture, following the planning principles of Le Corbusier. Residents were

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raised into the air in eleven-story buildings so as to keep the grounds and the first floor free for community activity.

The buildings were given communal corridors on every third floor to house rooms for laundry, storage, garbage, and communal activities, which disassociated from all units, were unsafe. They were soon covered with glass and garbage. The mailboxes on the ground floor were vandalized. The corridors, lobbies, elevators, and stairs were dangerous places to walk through, and were covered in graffiti and littered with garbage and human waste. The elevators, laundries, and community rooms were vandalized, and garbage was stacked high around the non-working garbage chutes. Women had to get together in groups to take their children to school or go shopping. The project was torn down some ten years after its construction.

However, across the street from Pruitt-Igoe was Carr Square Village, an older, smaller, rowhouse complex occupied by an essentially identical population. It remained fully occupied and trouble-free throughout the construction, occupancy, and decline of Pruitt-Igoe.

With the social variables constant in the two developments, what, Newman asked himself, was the significance of the physical differences that had enabled one to survive while the other fell apart? Walking through Pruitt-Igoe when crime and vandalism were pervasive, he could only wonder: What kind of people live here?

However, within the development there were occasional pockets that were clean, safe,and well-tended. These were found where only two families shared a landing. If one could get oneself invited into an apartment, one found it well maintained — furnished modestly perhaps, but with great pride. Why was there such a difference between the interior of the apartment and the public spaces outside it?

From this and other examples of contrasting situations, Newman concluded that residents maintained, controlled, and identified with those areas that were clearly demarcated as their own. Landings shared by only two families were well maintained, whereas corridors sharedby 20 families, and lobbies, elevators, and stairs shared by 150 families were disasters — they evoked no feelings of identity or control. Such anonymous public spaces made it impossible for residents to develop an accord on what was acceptable behaviour in these areas, impossible for them to experience or exert proprietary feelings, impossible to tell resident from intruder.

Oscar Newman looked at these questions in his book, Defensible Space in 1972, and said that the key was to make residents become the critical agents in their own security. Newman believed that firstly, design should propagate ‘natural surveillance’, generating opportunities for people to see and be seen continuously. Knowing that they are, or could be, watched makes residents feel less anxious, leads them to use an area more and deters criminals by making them fear being identified and caught. Secondly, people must not only watch but also be willing to intervene or reportcrime when it occurs. Newman proposed reducing anonymity and increasing territorial feelings by dividing larger spaces into zones Oscar Newman looked at these questions in his book, Defensible Space in 1972, and said that the key was to make residents become the critical agents in their own security.

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Newman believed that firstly, design should propagate ‘natural surveillance’,generating opportunities for people to see and be seen continuously. Knowing that they are, or could be, watched makes residents feel less anxious, leads them to use an area more and deters criminals by making them fear being identified and caught. Secondly, people must not only watch but also be willing to intervene or reportof influence. This can be accomplished on a small scale by clustering a few apartments around a common entrance.

On a larger scale individual yards or areas can be demarcated by having paths and recreational areas focus around a small set of apartment units, or by having each building entry serve only a limited number of apartments. Thus he envisaged the architect creating in residential areas an intricate hierarchy of public, semi-public, semi-private and private domains.

Newman considered man as a territorial being, as a being that needs territory as he needs water, in order to be able to live a satisfactory life. He posited that man is not basically criminal — preferring social cohesiveness to anarchy, social harmony to tension. Providing surveillance over defensible spaces allows man to be in his natural state, surveying and defending his domain.

Newman and his followers tested these ideas by studying housing developments in cities across the USA, from New York to San Francisco, and concluded that rates of crime, vandalism and turnover were lower in places that conformed to the principles of Defensble Space. While the results have not been consistent, reductions in crime and fear and increases in a sense of community have been found in several places. The concept of Defensible Space enabled residents to take back control of their neighbourhoods and reduce crime.

The problem with the typical terrace house situation is that the street outside the gate is considered ‘no man’s land’. Residents of terrace houses have no control over the space just

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outside their homes, over the people who use it or what they do — similarly with the green spaces, the social amenities provided by the developer or government. There is no sense of ownership, and they therefore fall victim to neglect and vandalism. Using Oscar Newman’s analysis it is understandable why, but also it is possible to think of how to overcome this problem.

The tessellation layout design assists in providing natural surveillance of the external spaces whereby every house lies in a cul-de-sac, which naturally produces defensible spaces – the hierarchy of public, semi-public, semi-private and private domains as prescribed. Here, public safety is engendered by neighbours looking after each other.

Furthermore, in contrast to the typical terrace house neighbourhood, it completely eliminates back-lanes from where 70% of break-ins in Malaysia originate.

Communal surveillance can be further augmented by close circuit or web cameras that are accessible on the TV screens or computer monitors of the residents. This sort of surveillance system is much cheaper than employing guards.

Recreation

Whilst adults and, to some extent, older children, are mobile and have a wider area to socialize, play and relax, small children in cities are largely restricted to their homes unless accompanied by adults. For this reason, the most important aspect of providing recreational facilities for residential areas is providing outdoor play areas for small children.

Just 40 years ago in Kuala Lumpur, the typical pre-schooler year old could go out to play the whole day and only come back for their evening meal. Nowadays, such children are most probably cosseted in their homes, ferried around to kindergarten, to music classes, and to playgrounds to play with friends, all under the close supervision of the parents or a maid. Play outside on the streets? Never!

Charles Mercer14, citing the work of John and Elizabeth Newson15 and proposed that play is an important aid to learning for the child; growing up can be seen as a process, where the

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child becomes more and more independent of the parents, exploring first the spaces around the mother and progressing to other rooms in the house, the front yard, and beyond. Mercer believes that the opportunity for exploring a new environment is best presented in small, discrete steps so that children can explore them at their own pace. The problem with the typical situation in urban areas is that the process of exploring new territory independent of the parents stops at the front gate. It is not considered safe beyond that. When the child is finally old enough to go out unaccompanied by an adult the transition is too big and he is disadvantaged as compared to a child that was able to explore bit by bit the neighbourhood around the home.

This suggests that the spaces outside the home should be made favourable to the growing-up process. They should be safe for smaller children with ample facilities for play. Football fields several minutes away from the home do not serve this function. The small parks in the middle of the courtyards should be designed primarily to meet the needs of small children.

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14 Mercer, Charles (1975) Living in Cities. Baltimore: Penguin.15 Newson, John & Elizabeth (1968) Four Years Old In An Urban Community. England:Penguin.

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Delft is a city in the Netherlands that is famous for creating a children-friendly environment, including the introduction of the “woonerf” or “shared street”16, where pedestrians have priority over cars. What they are saying now is that a city friendly to small children is friendly to all.

Greenery

Parks in the city also provide the main link with nature for city dwellers and have been described as being part of the “green infrastructure”. Indeed, parks and the flora and fauna they contain can be described as providing “ecosystem services”.

For example, large trees in urban parks reduce urban outdoor temperature through shade. They also lower ambient temperature through transpiration. Over 90% of the water absorbed by the roots is lost through stomata - small openings on the leaves. The evaporation of this water, akin to sweating, cools the surrounding air. A large tree will release 400 litres of air into the atmosphere.

The cooling effect of trees can mitigate the heat island effect. This has been shown in Singapore where a concerted effort to grow trees have been shown to change the surface temperature profile of the city state17.

Lower outdoor temperatures also moderate temperature inside buildings and so can contribute to reduce air conditioning load. A study in the US has found that shade trees on the west and south sides of a house in California can reduce a homeowner's summertime electric bill by about USD25 a year18.

16 Southworth, Michael; Ben-Joseph, Eran (2003) Streets and the Shaping of Towns andCities. Washington: Island Press.17 Tee Swee Ping, editor, “Trees of Our Garden City” National Parks Board, 2009

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There are also environmental functions that trees perform: perhaps most important one is delivered through their process of photosynthesis whereby carbon dioxide is used up and oxygen is released into the atmosphere. A mature tree can provide enough oxygen for a family of four; at the same time it will store about 3 tons19.

Trees can also act as an air filter and barrier help remove acidic pollutants and particulate matter. It has been shown that trees planted between industrial and residential areas can reduce particulate air pollution by 25%20.

The tree root system intercepts and retains rainwater helping to reduce peak storm water discharge and recharge ground water.

Trees also provide support and habitat for algae, lichens, mosses and liverworts, ferns, epiphytes and other parasitic plants. Many insects, birds, small reptiles and mammals also depend on trees for food and habitat. The presence of trees can bring a more diverse natural setting into urban scene to the benefit of city dwellers.

In addition to the many environmental functions that trees serve, there are more direct benefits of trees to people. There are numerous psychological benefits to be gained from urban parks and greenery. The experience of nature has been shown to avoid and relieve stress, improve mood and concentration, even make sick patients feel better21. This positive effect may be due to humans having had evolved for thousands of years in the natural environment, and only relatively recently have lived in towns and cities.

In conventional terrace housing in Malaysia, the benefits of trees and parks have been provided at the level of town and neighbourhood parks. Although trees are planted along streets, in front of houses, such trees have to be small. The road shoulder with its cables and pipes are not suitable for trees: but big shady species can thrive in the small communal gardens of the small neighbourhoods produced by Tessellation planning.

18 G.H. Donovan and D.T. Butry. The value of shade: Estimating the effect of urban trees on summertime electricity use. Energy and Buildings June, 2009, 662-66819 Tee Swee Ping 2009, pp 326-32820 David J. Nowak, “ the effects of urban trees on air quality”, USDA Forest Service, Syracuse, https://docs.google.com/viewer?url=http://www.coloradotrees.org/benefits/Effects%2520of%2520Urban%2520Trees%2520on%2520Air%2520Quality.pdf, retrived 17th January, 201121Rachel Kaplan, Stephen Kaplan, “ The experience of nature: a psychological perspective” , Cambridge University Press, 1989

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https://docs.google.com/viewer?url=http://www.coloradotrees.org/benefits/Effects%2520of%2520Urban%2520Trees%2520on%2520Air%2520Quality.pdf

https://docs.google.com/viewer?url=http://www.coloradotrees.org/benefits/Effects%2520of%2520Urban%2520Trees%2520on%2520Air%2520Quality.pdf


The clearing of trees to create concrete jungles are the main contribution to the heat-island effect. Maximizing the tree canopy area is the strategy used in the small neighnourhoods to minimise the heat island effect. With the profusion of big trees, small trees and shrubs, we can start thinking of landscaping not only in terms of beautifying the environment but as a source of food and habitat for small animals.

Inter-connected with neighbourhood and town parks with nature corridors, natural streams and rivers, the pocket parks just outside the home can be home to a diverse collection of flora and fauna more commonly found in low density, suburban settings. In such areas in Kuala Lumpur, or Singapore small mammals like the “tupai” (squirrels), civet and the long-tailed macaque are common, in addition to bats and numerous birds, including swiftlets, bats, storks and eagles.

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Drains

In a country with such a high rate of rainfall as Malaysia, storm water drains are important to avoid floods. During the early stage of urban growth in the country, rivers were widened straightened, and lined with concrete to drain water even more efficiently.

The aim was to achieve efficient and rapid disposal of storm water; the engineer’s main job was to determine the size and capacity of the drain and final discharge outlet was sufficient to meet the amount of water projected to enter the site. All drains to trunk drains are normally concrete-lined and of the open channel type to minimize the land area required22.

However this approach has been found to be inadequate to deal with the huge amount of water run-off resulting from rain falling on impermeable hard surfaces.

For an example study in Subang Jaya, a fully developed residential area, an increase in impervious area from 0% to 40% have shortened the time of concentration by about 50% and increased the magnitude of the run-off discharge by about 190%23

Further urbanization and consequent increase in paved areas would increase the incidences of flash floods not only in the newly urbanized areas, but downstream as well. Studies by Department of Irrigation and Drainage Malaysia show that few of the existing rivers would be

22 Embi & Kassim, Urban Drainage in Malaysia-New Policies and Strategies", Paper presented at the Seminar on Water Quality Management Mardi Serdang, l9-20 Feb 1998, Putrajaya Lake 23 K. Abdullah, " Masalah Banjir dan Manual Saliran Mesra Alam",Working Paper presented at the 24th Malaysian Town and Country Planning Senior Officers’ Meeting, 3-7 September, 2000, Port Dickson, Negri Sembilan

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able to cater for the expected increase in surface water runoff. The surface runoff from the development using the drainage system based on conventional approach will be double the current peak discharges. With this prospect, most of the major urban centres in Malaysia would be subject to unacceptable risk of flooding.

And so, the new Urban Storm Water Management Manual, was introduced in 2000, The main focus of this Manual is that instead of draining it away as fast as possible, a more environmentally approach known as “control at source” was adopted. Retention ponds played a key role here, not only to moderate run-off during peak rainfall, but to improve infiltration into the ground and minimize contamination of the water. Thus both the peak discharge quantity and quality are to be maintained to be the same as pre-development condition.

Engineers now have to ensure that for any piece of land to be developed, the peak discharge after fully developed must not be more than the peak discharge before development. In other words, there should be zero increase in peak discharge when any piece of land is developed. On top of that, there should be no reduction in the quality of water discharged out compared to that discharged before development.

With retention ponds the sizes of drains downstream need not be so big. Now, about 3% to 5% of any new development has to be set aside to be turned into a retention pond. Whilst this new approach makes sense, there is nevertheless an additional cost to be paid for by house buyers. At the same time, many of these ponds have not been adequately maintained and have become eyesores. In central urban areas, where land is expensive, developers have opted for underground on site detention ponds built below car parks , roads or any open space. These are even more costly and difficult to maintain.

The generous gardens and parks in a Tessellation layout provide an opportunity to explore an alternative solution that is less costly to build and maintain. In this approach, storm-water retention capacity is provided for within each home compound, in each courtyard, and in each neighbourhood. It is provided for in the home by designing the perimeter drain to be 50mm higher than the garden level, such that during heavy rain, the garden will flood up to 50mm before the water spills over into the drains.

Typically, the home is able to retain 2.5 cubic meters of water and each small park. 15 cubic meters.

In a large Tessellation layout which also provides a neighbourhood park, the park can also serve as what is called a “dry” pond.

With careful design, the need for 3% to 5% of the development to serve as retention pond can be partly omitted. Moreover, because water is retained very near where it falls, (exactly according to the principle of “control at source”) the sizes of the drains within the whole development can be downsized.

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Area of Gardens and Pocket Parks acting as Dry Ponds

For example, in this city development setting aside 0.7 acres of land, foregoing USD 0.5 million of value. The adopted alternative was to build underground detention tanks having the same retention capacity of a retention pond on the ground would only cost USD300,000. The pocket parks make up more than 7% of the total development land; the gardens also make up a substantial amount - more than 10%. By raising the level of the side of the drain

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Housetype Area (sm) Units Total Area (sm) % Area

A 100 2 200

B 20 100 2000

C 50 65 3250

5450 10%

Pocket Parks 3967 7%

Total Development Area

56672 100%


or surface water outlet by 50mm, the green areas inside and just outside the house can act as dry retention ponds.

Similarly, the small park in the courtyard is also designed to flood. When it rains heavily, the gardens and small parks are designed to fill up with water before it spills over onto the drains and discharged downstream.

Taking into account only the retention capacity, this is equivalent to half of the calculated volume of retention capacity required by the site. Thus half of the USD300000 cost of constructing underground detention ponds would be saved. However, compared with the OSD, the large surface area of gardens and parks can absorb and slow down rub-off much better than a concrete tank or a retention pond.

Sewerage

For urban centres where the population is concentrated sophisticated treatment systems have evolved, which produces a high quality effluent. The cost of servicing and monitoring these tanks is expensive. There are economies of scale in providing the building of these centralized treatment plants. On the other hand, a centralized sewerage treatment plant serving a big area will require long distances of deeper and deeper sewer mains.

By contrast in the countryside, individual and community septic tanks suffice because the surrounding environment is able to tolerate the relatively low level of effluent pollution.

Septic tanks suitable for up to a population equivalent of 150 where, effluent discharges will not adversely affect the environment. It is a cheap solution to disposing of sewage. This type of sewerage treatment only partially treat sewage and concentrated groups of tanks can overload the capacity of the receiving environment creating health and odour problems.

Furthermore, these tanks have to be serviced to ensure their proper working.

Small neighbourhoods can also adopt small scale package systems. However, because of their size, small communities have traditionally faced the problems of high per capital costs, limited finances and limited operation and maintenance budgets for sewage treatment.

Cluster systems bridge the gap between the centralized and individual septic tank systems. In this system, septic tanks are still used for primary treatment, but discharge their liquid effluents into small diameter pipes which then flow, by gravity or pump, to a centralized facility for secondary treatment before the effluent is finally discharged into the environment.

Main sewer lines are 230mm diameter or larger and require deep invert levels to maintain flow by gravity. Using the cluster system, the effluent pipes start from just 30mm thick and work with gently gradients besides being easier to pump. Hence, the cost of constructing sewer lines can be reduced.

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For Tessellation planning’s small neighbourhoods, it is proposed that community septic tanks are placed in each cul-de-sac. The small parks in the courtyard can easily accommodate these tanks. Placed below ground, the use of the park for planting trees and for recreation need not be compromised. The advantages of having a community septic tank rather than individual tanks are that it is cheaper per household and it is easier to de-sludge, maintain and monitor.

Average Wet Water for Various PopulatiosMinimum

Septic Tank Stiller Tank

Population

Flow/ Person (litres/day)

Design Daily Flow, (litres per day)

Capacity (litres)

Capacity (litres)

25 380 9,5

00 19,000

3,800

80 380 30,4

00 60,800

7,600

250 380 95,0

00 190,000

11,400

For example a courtyard containing 16 houses will require 2 tanks, each with 36,000 litres capacity, diameter 2.500 mm and length 7,784mm. The stiller tank is a tenth of this size: diameter 1.500 mm and length 4,768 mm.

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The courtyards in the cul-de-sacs are naturally too sensitive to receive effluent, so it is allowed to flow or pumped into pipes of less than 40mm diameter to another location for secondary treatment before discharge to a more suitable receiving environment.

Solid waste disposal

Refuse collection from every household and transporting it to proper landfills or incineration plants can be expensive. Joint action at the local community level can help reduce the volume of rubbish that needs to be transported. The typical household contributes between under 1 to 1.5 kg of rubbish per day24

Small neighbourhood solid waste disposal would aim to:

overcome the problems of dirty and unhygienic surroundings that we find now in many neighbourhoods,

help increase the amounts of garbage that is recycled, reduce the amount of solid waste that has to be taken to be transported out.

In all areas that we have surveyed, garbage waiting to be collected, often stinking, is a magnet for stay cats, dogs, rats, flies, cockroaches and other vermin. This is caused by organic waste, especially food leftovers. It is estimated that in Malaysia over 40% of

24 Mohd. Badruddin Mohd.Yusof, et al, “The role of socio-economic and cultural factors in municipal solid waste generation: a case study in Taman Perling, Johor Bahru”; Jurnal Teknologi, 37(F) Dis. 2002: 55–64, Universiti Teknologi Malaysia

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household waste is made up of organic food waste. An important step would be to eliminate this source of the problem of odour, vermin and mess.

One easy solution is to provide electric grinders or “food waste disposers” under the kitchen sinks of all houses (a common practice in America, Australia and Europe) to get rid of food waste at source. The grinders discharge directly into the main sewer line leading to the communal septic tank, which may need to be upsized. Field trials in several countries have shown that these food waste disposers do not affect water usage or accumulation in sewers significantly 25.

The simple removal of digestible organic matter directly into the existing sewer system means the rest of the garbage can be clean and dry, and does not need to be put out every day.

Other organic waste that is not suitable for the grinder, in particular from gardens can be composted. A community of 5 or more household is a good size to maintain a communal composting bin.

25 Tim Evans, “Environmental Impact Study of Food Waste Disposers”, for The County Surveyors’ Society, Herefordshire Council and Worcestershire County Council; Synopsis by J Howell-Thomas, Worcestershire County Council

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Another step is to make recycling of tins, plastic, bottles, newspaper in the small community easy and profitable. Recycle bins in each cul de sac can be provided so that recyclable waste is sorted at source.

On the other hand, the community refuse bin for unrecyclable, unsorted rubbish can be located a certain distance away from the houses, not only to avoid it becoming a nuisance to the residents, but also to make it a bit tiresome for residents to throw their rubbish this way. Thus householders are encouraged to use their grinder, and to clean and put aside recyclables.

In Malaysia today only 5% of waste is recycled. We would be aiming to have 20% of household waste recycled (the average for advanced countries). The expected benefits are listed below:

Current Target, Target,

Improvement %as % of current total %

Recycleables glass, metal, plastic and paper 5 15 15%

Community segregated rubbish collection

Compost 0 15 15% Community ComposterGarden Waste 20 5 5%

Kitchen Waste 40 20 20%Kitchen Grinder to sewerage system

Other non reycleable 35 20 20%

Current Total 100 75 10025% reduction in overall volume

Reduction in Garden Waste, Kitchen Waste, and non recycleables

15%

20%

15% 50% reduction in landfill volume

These targets are based on an experimental community project in Petaling Jaya undertaken by an NGO, Centre for Environmental Technology and Developement Malaysia (CETDEM)26

Conclusion

The Neighbourhood Unit concept envisaged a network of open areas making up 10% of the development area but with a neighbourhood park in the middle of the neighbourhood.

26 Community Initiative on Household Waste Composting in Petaling Jaya, (CHC@PJ/2008-2009) CETDEM, 2009

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However, Tessellation planning layout gives priority to small parks dispersed throughout the development located to provide a green area in front of every house.

It has been argued here that these parks serve as a valuable amenity for recreation, especially for children’s outdoor play and to engender a sense of community. Tessellation layouts also help in creating a neighbourhood sheltered against the dangers of crime and traffic. In this paper, we further leverage the availability of open space and the potential for neighbourly cooperation by using the open spaces to help provide urban infrastructural needs.

Whilst in many countries like Malaysia the the provision of 10% of the development land as open green area is mandatory, in many other countries, there is no such requirement. In these countries, the use of the small parks to accommodate infrastructural facilities like communal septic tanks, dry retention ponds, compost bins, recycling bins is an added justification to providing these open spaces.

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Mazlin - Small Urban Neighbour Hoods

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