Site planning

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This section amplifies some of the planning principles discussed in Chapter 3 and 4. There are many publications explaining the planning process, some of which are listed in the Bibliography. The importance of consultation with all the parties involved with this process has been stressed on many occasions in the manual. Two useful publications which explain planning within the context of participatory development are: Goethert, R & Hamdi, N.1988. Making microplans. and Taylor, L. & Jenkins, P. 1989. Time to listen - the human aspect in development. (both from Intermediate Technology Publications, London).

More detail on the principles of site planning and appropriate standards that can be used in an urban context are contained in the following publications:

· De Chiara, J & Koppelham, L.E. 1978. Site planning standards, New York, McGraw-Hill Book Company;
· Cartwright R.M. 1980. The design of urban space, London, The Architectural Press Ltd.; and
· Lynch, K. & Hack, G. 1984. Site planning, Cambridge, MIT Press.

Site planning objectives. The project goals described in Chapters 2 and 3 will provide a general basis for the preparation of a physical master plan. These general goals need to be supplemented with more detailed objectives, which will be used both in reviewing site planning options and in the development of a preferred option into a draft, and then final, master plan. Care needs to taken in establishing these objectives as it is a common error of site planners to assume values which are in conflict with the values and habits of the site's users. There are, however, a range of general objectives which provide a useful starting point for developing more appropriate objectives suited to the conditions and culture in which a particular market is to be developed.

The most obvious of these objectives is functional adequacy; a plan must accommodate all the needs defined by a project's goals. It must also provide optimum communications, both in the sense of traffic movement (as a market is primarily a complex transhipment point) and social interaction (as it is a point at which sellers and buyers meet to conduct business). Choice and adaptability are important objectives, as change is inevitable with any market and the success of a plan in the long term will depend on its provision for users to mould and adapt it to their particular requirements. Minimum standards of public health, sanitation, accident prevention and structural safety will also need to be considered.

Although architectural quality may not be a main interest of either the market's developers or its users, this should not be forgotten. Cost, however, will always be the main criterion, but this must always be related to other objectives, with which it will frequently be in conflict. The main problem will be to strike a balance between that of minimizing initial capital costs and reducing the recurrent maintenance and operational costs of running the market.

Table 13.8 Kalimati wholesale market Nepal: space requirements (m²)

Source: FAO Technical Report, GCP/NEP/043/SWI
Notes: + Excluding paved areas associated with buildings, covered arcades and paving to the farmers' market area.
# Including temporary construction roads

Site planning options. As the starting point of the site planning process, different options should be generated to reflect the design objectives.

These options, will form the basis of the draft master plan and a typical approach to reviewing them is to start with an analysis of land uses on the site, derived from the accommodation brief. The main categories of land-use activities need to be identified and the relationship or linkages between them established. These linkages may be of a physical nature, such as roads, or more abstract, such as a flow of information. Linkages are more usually positive, but some may be negative. This could represent, for example, an incompatibility between uses, such as between a refuse disposal area and on-site residential accommodation.

Different diagrams or patterns should be created for each option, which will represent a simplification of the design problem to its logical essence. The options will need to be analysed, which will generally be based on how satisfactorily they perform in terms of cost and of minimizing time spent within the market. Although simple physical distance will give some indication of this, the effects of congestion in a market are critical and therefore time is a more relevant measure. The reviewing of options will provide an initial sorting out of ideas, which will need to be developed further during detailed design. The choice of planning options can be most practically understood by using a simple ranking system based on the site planning objectives discussed above.

Land-use analysis. The estimates prepared of space requirements for the buildings should be related to that of the whole site. Table 13.8 shows an illustration of a phased estimate of the market buildings needed for the Kalimati site in Nepal, including the space requirements for the ancillary and service buildings, and for a 2,000 metric ton cold storage facility. In the estimate an allowance was made for the substantial parking provision and road system which will be needed by the market at ultimate development. Although present retailers at the market may continue with the use of small hand carts, this pattern is likely to change rapidly with the introduction of small pick-ups and trucks.

Table 13.9 gives a comparable land use pattern for the Sansai market in Chiang Mai, where a large proportion of the site was allocated to traffic circulation needs. As discussed in Chapter 4, the main factor to consider in land-use analysis is the proportion of a site that is given over to roads and parking and in Table 13.10, which compares the land uses in three Near East wholesale markets, the importance of this is evident. The extreme congestion of Rod al Farag market in Cairo, for example, is explained by its lack of road space and traffic management, combined with restricted access in the roads leading to the market. The market is over-intensively used compared to its overall site area, although the turnover per m² Of sales space of 15.7 tons is not that high.

Table 13.9 Sansai Market Centre, Thailand land use (m²)

Source: FAO Technical Report - TCP/THA/8958

Table 13.10 Land-use analysis of Near East wholesale markets

Source: FAO

Site master plan. The purpose of preparing a master plan is to provide a document, primarily a map or series of maps, supplemented by written statements, drawing together the synthesised information from the previous design stages and providing a basis for consultation and more refinement of the detailed design. The main function of the plan must be to maximize the throughput of the market, while minimizing capital and operating costs.

The basic approach will be to compile all the planning data, including the land-use projections and any diagrams prepared of market operations (such as in Figure 15) and plan options in order to draw them to scale (typically at 1:500, 1:1,000 or 1:2,000 scales), so they can reflect the actual accommodation requirements related to the circulation pattern and can be fitted within the confines of the site boundaries. The first draft or outline master will clarify what are the opportunities and constraints to development on a site. An example of the evolution of such a drain master plan is shown in Figure 30.

This will be a stage at which many sketches are made so that adjustments can be made which rationalize the relationship between the land uses and provide the most efficient access and traffic circulation system. The original neatness of sketch diagrams will often to be lost at this juncture, as the plan gets modified to meet the site's physical conditions, climatic considerations and the evolving requirements of the design brief. However, although the influence of the local site is important, the essentially functional nature of markets will tend to lead to solutions in which the general form is compact and geometrically regular, using standardized building forms.

Important factors that need to be considered in the plan are how the development might be phased and how the separation of permanent uses from those which are of a more transient nature can be used as a means of organizing the site so that future changes can be most easily accommodated. As roads and parking areas arc likely to be a major element of the total capital cost and are elements which can be varied substantially in both extent and standard of construction, they will be a major consideration in determining the ultimate form of the outline plan.

The easiest way to undertake an analysis of the plan is to measure the overall site area of each of the proposed land uses and prepare a table which relates them to the overall site area. The methods of measurement for preparing the table can vary from using a planimeter, to counting squares on a graph paper overlay, The important issue to remember is to always compare the measurements to the known overall area of the site. This tabulation can then be compared to Table 13.8 - 13.10 which gives typical values for the utilization of land at a variety of market sites.

Figure 30 Evolution of a draft or outline master plan (Sansai, Thailand)

The difference between an outline plan and master plan is one of detail. As the consultation process continues and the detailed design evolves the land-use pattern will be transformed by the actual designs for buildings and infrastructure. Two key issues that will need to be addressed in developing the final master plan are:

· how to evolve an arrangement with a satisfactory relationship between the site circulation system, unloading and loading areas, general parking and the internal arrangement of the main market buildings; and
· how to organise the site layout so that construction phasing is simplified and future growth and changes can be accommodated without disruption.

These issues are critical to a plan's success, particularly if there is any reluctance on the part of wholesalers to move to a new location or cooperate in the implementation of improvements to an existing market. Increased rents for premises will need to be justified on the basis that they will be offset by a well-designed market providing other benefits, such as lower operating costs (see Chapter 5). The potential savings from an improved or new layout include: adequate parking spaces and loading bays leading to increased vehicle turn-around, with less time lost for both wholesalers and retailers;

· compact building layouts with less manual handling of produce, leading to lower porterage and labour costs and a more efficient use of warehouse space;
· covered sales and handling spaces, giving protection from rain and sun, leading to reductions in deterioration of produce; and
· introduction of controlled entries and exits, leading to reductions in pilferage.

A study by the US Department of Agriculture in 1947, for the relocation of the wholesale fruit and vegetable market from a central area site in the middle of Atlanta (Georgia) to a new site outside the city,, estimated that the savings in annual operating costs would be made-up as follows:

Another example of the level of economies that can be obtained from improved facilities is shown in Table 13.11.

Table 13.11 Comparison of costs affected by facilites used by produce firms at the Maryland Wholesale Food Center (US $ per Imperial ton)

Source United States Department of Agricullure/Maryland Food Center
Authority. 1989. Wholesale Food Distribution Center Growth and Development, USDA, Washington DC.

Building design

The purpose of architectural design is often forgotten in the design of functional building types such as markers. It is assumed that by applying a simplified standard model (often copied from another site or country) an acceptable solution can be arrived at which will avoid the necessity and expense of having to employ an architect or engineer to design the market buildings. In reality, this is most unlikely to be satisfactory.

The only way that market buildings can be created to match the site and climatic conditions, the proposed management system, the level of technology of the country and the cultural context is if they are consciously designed. To arrive at inexpensive and appropriate building forms, albeit of a flexible and expandable nature, will require the market authority to involve itself with fully briefing any design consultant.

The writings of Christopher Alexander (1977. A pattern language towns buildings construction. New York, Oxford University Press) provide a comprehensive understanding of this design process. Examples of how architectural design principles can be applied to building types in less-developed countries are given in: Maxwell Fry F. & Drew, J. (1956. Tropical architecture in the humid zone. London, B.T. Batsford Ltd);

Figure 31 Internal layout of a typical wholesale market (Kalimati, Nepal)

Koenigsberger, O.H. et al. (1973. Manual of tropical housing and building -part 1, climatic design. London, Longman); and Saini, B.S. (1980. Building in hot dry climates. Chichester, John Wiley & Sons).

Building form . The initial task in selecting an appropriate arrangement for the buildings will be to understand the operation of the market, how produce will flow and how it will be managed (see Chapter 8). The designer will probably present this in the form of simple flow charts, elaborating those prepared during the site planning stage. To give these diagrams an architectural form is a complex process which can only be briefly touched upon in this manual.

As the first step, the market authority, preferably in conjunction with the designer, will need to prepare an accommodation schedule, specifying the overall estimates of space requirements. The basic choice of building form will also need to be made (see Chapter 4, Figure 8). A series of geometrical patterns, derived from ideal dimensions for the range of activities in the market, will then be applied by the designer to the accommodation schedule. The designer will prepare a series of sketch designs which "balance" the internal space and circulation requirements of the buildings with the need for flexibility in use and constructional simplicity. This is an iterative process, requiring constant consultation with the market authority and traders. In this process designers use a wide range of physical design data and techniques, including ergonomic and anthropometric standards, planning grids and structural modules (see Chapter 14).

Planning grids One of the key determinants of the planning grid will be the optimum size of sales areas and wholesalers' stalls. If they are over-sized this is likely to lead to a low turnover (less than 15 tons m²) and an underuse of resources. As a consequence rents are likely to be disproportionately high as cost recovery normally requires that rents should not exceed 2 - 3 percent of the value of sales. For existing buildings the survey of facilities described in Chapter 11 should help to establish current practice by, for example, tabulating the number of stalls of a particular size. Typical values for these modules are shown in Table 13.12 but these figures should be used with caution as they may not match local circumstances. The ideal method is to use the minimum of fixed walls so that premises can be defined by moveable partitions, usually constructed of steel mesh. A typical plan showing the relationship between producers' sales areas, wholesalers' premises, a buyers' walk and supporting facilities is shown in Figure 31.

Other dimensions. As well as the horizontal or (plan) dimensions of the sales areas there are a number of other key dimensions which will influence the building form. These include the dimension of parking bays (see Table 14.1), which should be related to both the width of structural bays and to the dimensions of the sales areas. Vertical dimensions are also important and, if not carefully considered, may restrict the flexibility of the building to accommodate changes in operating procedures.

The preferred minimum clear vertical dimension for market halls is 5 metres, which will allow small fork-lifts or powered pallet-trucks to be used in the future. If any form of racking and block storage is envisaged, a more suitable internal minimum height is 7.5 metres, again clear of any obstructions caused by the roof structure. Minor spaces, such as offices and other ancillary uses should have a minimum height of 2.4 metres.

Door openings through which fork lift trucks may need to pass should be a minimum of 4. 2 metres high and preferably 6 metres in width.

Another issue that will need to be resolved is how far the floor slab of the market buildings should be raised above ground level. Market buildings are often raised 0.9 - 1.2 metres to facilitate loading banks or platforms. This is an expensive element to construct and may lead to cracking problems with the floor finishes. It also imposes restrictions on how the building may be used. The better solution is to have a 0.2 metre changes of level, with permanent or temporary shallow ramps.

Table 13.12 Dimensions of wholesalers' units at selected markets

Source: Mittendorf H.J. 1976. Planning of wholesale markets for perishable food, Rome, FAO.

Climatic design principles The building form will also be strongly influenced by climatic design factors, relating to the general climate of the country and to specific micro-climatic features of the site. The traditional building forms in an area will provide evidence of how buildings have been designed in the past to cope with the climate. However, the particular problems created by the need to build a modern wholesale market using a minimum of sophisticated technology makes a review of climatic design essential if comfortable conditions are to be achieved for the building's users.

There are three basic types of climate that are common in less-developed countries, which will have different implications for the siting of buildings, their internal layout and their construction.

· warm, humid climates: typical of the equatorial tropics and tropical islands, with high humidity and rainfall levels. The main characteristic of buildings in this climate is that they should be planned to minimize solar heat gain and to maximize air flow. The orientation of buildings should ideally be on an east-west axis, spaced at a minimum of five times the building's height to allow breeze penetration. Rooms in the building should be single-banked to allow cross-ventilation, with large openings (40 - 80 percent of the wall area) and positioned on the north and south elevations. Walls should have a low thermal capacity. Roofs will need to be insulated (see Chapter 14) and should have wide overhangs to prevent sun penetration and to give protection from heavy monsoon rains and high (sometimes hurricane force) winds.
· hot, dry (arid) climates typical of desert and steppe areas, with high temperatures and ground glare, and low rainfall levels. The buildings in this climate should be planned as compactly as possible in a courtyard form with precautions to prevent entry of hot dry winds.

Cross-ventilation to rooms is not essential and openings should be limited to 20 - 40 percent of the wall area. Walls and roofs should have a high thermal capacity, with shading devices to control sun penetration.
· composite climates: typical of equatorial and tropical uplands and Mediterranean areas, combining the problems of both humid and arid climates. Building design is ideally similar to arid areas, but with facilities to take advantage of solar radiation at cooler times of the year and temporary provision for cross-ventilation.

Architectural elements. Other factors that will influence the form of buildings will be the positioning of internal and external fixed elements, some of which have already been commented upon in Chapter 4, whilst others are discussed in Chapter 14. The following is a brief check-list of these elements, which may need to be incorporated into the design:

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