Once the site, the location and the general service requirements have been settled, the next important subject is the total floor area required and its allocation between the various sections of the kitchen and storerooms.
Too little attention has, in the past, been paid to the important question of correct size, with the result that the efficiency even in some modern kitchens is impaired either because the total area is inadequate or less frequently, because the kitchen is too large for the work carried out.
The difficulties of a kitchen where the working area is too small are mainly due to congestion. Equipment, utensils and the workers themselves occupy a certain amount of floor area, and unless there is in addition sufficient space for the free movement of workers and utensils and for the operation of the equipment, the work will take more time and energy than is absolutely necessary. Other difficulties in kitchens which are too small for their output are ventilation and temperature control. People who have worked in very small kitchens know only too well the discomfort of high temperatures and steam laden atmospheres, and those who have tried to improve conditions by artificial measures know how difficult it is to do this satisfactorily.
A kitchen where the architect has been over-generous in his allocation of floor space presents different problems. Those which chiefly concern the worker are the demands made on his time and energy by the distances to be covered. Kitchen work entails in all processes a considerable amount of walking and carrying, and it is obvious that if the lines of communication are unnecessarily long the energy expended and the time taken for each section of the work will be greater. The increased cost resulting from the additional cleaning, lighting, heating, maintenance and staffing required is another disadvantage of an over-large kitchen. A good general concept is “plan minimum amount of space for maximum job”.
The previous remarks refer only to the actual working space in a kitchen and not to the store room areas. It is so unusual to find a kitchen where the storage accommodation is excessive that it is difficult to visualize the disadvantages of such a situation: in fact storage accommodation would have to be very generous before it presented any problems. The problems of inadequate stores are so obvious that there is no need to enlarge on them.
Factors influencing the total area
Before any range of areas can be recommended as satisfactory for kitchens and ancillary rooms, one must consider the factors which affect the work of the kitchen and consequently the floor space required.
(a) Kitchens can be broadly divided into two main types, namely, those for residential institutions such as college halls of residence and boarding schools, and those for such non-residential establishments as schools and factories where the main bulk of the work lies in providing a hot meal in the middle of the day. The extent of the work determines the number of staff and the amount of equipment required, and although there are variations even within the two groups enumerated, it is reasonable to assume that the residential institution will require a larger allocation of space than a comparable non-residential establishment.
(b) The number of meals served more than any other single factor, determines the size of a kitchen; but in arriving at this figure one must be quite clear as to what is meant. In the case of a non-resident institution no confusion arises, for the number given would obviously be the number of midday meals. In a residential establishment, however, a difficulty might arise if the total daily number of meals were stated, and it might be better if the term “number of residents” were used in place of the term “number of meals “. But even this would not be sufficient if there were any possibility of a number of non-residents and staff being served with the residents at any time as for example in the middle of the day. In such a case it would be better to use the figure of the largest number of meals which is likely to have to be produced at any one time.
(c) Less equipment and staff will be required to produce a meal where the menu consists of two courses only, without any choice, than to produce a three or four course menu where there is a choice of dish in each group. We must therefore bear this in mind when considering space requirements.
(d) When considering the overall area it is important to take into account the demands for such ancillary rooms as staff dining rooms, offices, cloakrooms and lavatories, and to ensure that adequate floor space is allowed for these if they are to be provided within the total space allocated for kitchen use.
(e) If the space allocated to the kitchen premises is of an awkward shape, the total area must be larger than that required under normal conditions. This may happen in new buildings where supporting pillars may project into the room, but it is much more common in existing buildings which are being adapted for canteen use. In such cases one may have to plan kitchens in a series of small rooms where the dividing walls can be only partially removed and where there are small recesses which are quite useless for kitchen work but which add to the overall area. The total area required in such cases would be considerably more than that which would be satisfactory without these inconveniences.
(f) The point to be made here is that there are some widths of buildings which are more suitable for kitchen planning than others, and that if a building of unsuitable width has to be used as a kitchen the overall area required will be greater than in a building of satisfactory width. The reasons for this are the shape and size of the equipment to be fitted, and the widths of the passageways to be allowed. An interesting example of this difficulty occurred during the war when huts of standard span were erected as kitchens. Huts of 18ft. and 24ft. span were available, and it was found possible to prepare an efficient kitchen layout more easily and with greater economy in the overall area when using the 24ft. span than the 18ft. span.
(g) The best shape for a kitchen is either square or rectangular with the length not more than twice the width.
Allocation of the total area
When the total area requirements for the whole of the kitchen premises have been decided the next point to consider is the division of the floor space among the various sections. The two main sections are the ancillary rooms and the kitchen itself, i.e. the actual area devoted to preparing, cooking and serving the food and to the washing up.
The Ancillary Rooms
The number and uses of these rooms varies according to the size and requirements of the kitchen. Thus in a small kitchen there may be only one storeroom used for all purposes, whereas in a large establishment separate stores may be provided for vegetables, dry goods, empty cases, bread, wines, china, cleaning materials and reserve equipment. Again, in a small kitchen the only staff accommodation required will be a small cloakroom and lavatory, whereas in a large kitchen, cloakrooms, lavatories, dining rooms, offices and even rest rooms are provided.
Some variations occur in the type of storerooms provided in large kitchens. In some the main storage accommodation consists of a dry store for all the main bulk goods, a larder for cooked foods which must be kept cool, and a refrigerator for meat, fish, dairy produce and other perishable goods, and some 0°F. to 57. for deep frozen foods. In other kitchens there is no larder, built-in refrigerated rooms being provided instead. There may be a number of these in large kitchens so that meat, fish and other perishables may be kept separate. A range of temperatures is needed for different categories of food, and this is dealt with in Chapter 9 and Chapter 16. If a large quantity of dry goods is kept, it is convenient to have two separate rooms so that the more bulky goods in sacks and cases may be stored separately from the smaller articles.
The whole question of the amount of space required for storage is dealt with in detail in “Residential Catering ” and recommendations are made for all supplies for young people for 3 meals a day for a 7-day week. The total floor areas are given for dry store, bread store, vegetable store, cool store, cold store and deep freeze, for meal capacities ranging from under 100 up to 800. Graphs summarizing these recommendations are shown in Fig 10.
The space allocated for the preparation, cooking and serving of the food, and for the washing up, must be adequate to allow for the placing and operation of all the equipment to be used, including tables and working benches. In some kitchens the areas used for the various preparation processes are separated from the main kitchen. Thus there may be separate rooms for the preparation of vegetables, meat, fish and pastry. This arrangement has its advantages particularly for the vegetable section where the noise of the potato machine and the unavoidable dampness of the floors, are a nuisance to the other work of the kitchen. There are, however, disadvantages. The dividing walls cut off the light and interfere with ventilation, the supervision of workers is more difficult and it is, moreover, not as easy to plan an efficient kitchen layout on this system. The advantages of separate sections can be obtained without erecting dividing walls, by planning so that the work of preparation is done in different parts of the kitchen.
Opinion differs on the question as to whether the servery should be separated from the kitchen or not. In the past it has often been recommended that there should be a separate compartment with a wall cutting off the view of the kitchen from the dining room. Such an arrangement, however, does not facilitate efficient transport from the cooking to the serving area. As pointed out in Ministry of Education Building Bulletin 11, the saving of time and energy is of much more importance in those areas of a kitchen where there is a great deal of movement each day than in those where movement is less frequent. Thus the relationship between the areas where cooking, dishing-up and serving takes place should be closely knit if energy and effort are to be saved. Fig. I show’s clearly how such an integration can be achieved and the saving of movement which would thereby be effected. It is claimed that a saving of about 65 per cent of the movement necessary in carrying food is possible in the layout planned for work sequence (a) compared with layout (b).
Another method of achieving close integration between the kitchen and servery without having the kitchen exposed to view is by the provision of hot and cold pass-through cabinets in the dividing wall. The hot cabinets can be small boxes opening on both sides and capable of holding two deep rectangular serving dishes. They are most convenient if fitted with a glass viewing panel thus making it unnecessary to open the door to see the contents and thus cause cooling. The cold cabinets are most convenient if they can be used with mobile racks which can be loaded with salads or cold sweets before being pushed into the cabinet. Plate XX shows this type of fitting viewed from the kitchen.
In making recommendations for the size of the servery there are two points to consider, namely its width and the length of the service counter. The traditional type used either for waitress or cafeteria service consists of a long counter provided with a tray slide. The length is to some extent related to the number of meals served and ranges from 20ft-50ft, a useful average length being 30ft. When seating accommodation exceeds 300 it is preferable to have an additional servery rather than to increase the length which is to a great extent related to the number of items displayed.
These are usually divided up into hot and cold sections and beverages which may be located in different serveries physically separated from each other to permit breaking the queue for those not requiring a complete meal. The width of the servery is made up of 4-44 feet for the serving aisle, with if needed an additional 2 feet for the back counter.
The efficiency of a service counter can be judged by the speed of flow of the customer which ranges from 7-14 per min., 10 being a good average. New ideas for speeding up this flow have resulted in the hollow square servery where various categories of food are displayed in different areas so that the customer does not need to queue and can go to a free space for service at will. This system, known variously as Scramble, Free-flow, shopping center or supermarket, is dealt with in more detail in the next chapter. It is probably more useful when the number of meals served is 600 or more and the area necessary is about 2,000 sq. ft.
Space requirements for the wash-up, the planning of which will be dealt with in the next chapter, are related to the number of meals served, the type of dishwasher installed and the length of time available for the dishwashing operation. In a school meals kitchen it is usual to install a unit consisting of one washing and one heated rinsing sink which will deal with the dishes for 300 meals in two hours. Two of these installed on opposite walls with a 5ft. aisle between in a room about 15 ft. long would be adequate for 500 meals (see Fig. 9). Mechanical dishwashers which are usually installed down the middle of a room and range in length from 6ft to 20ft, require sufficient space to accommodate them comfortably with an adequate surrounding area for stripping and sorting dirty dishes, drying and stacking of clean dishes and parking space for trolleys for transport. In a recent survey of wash-ups in Canada and U.S.A. satisfactory areas were seen ranging from 608 sq. ft. (16 x 38) for 800 meals and 1,568 sq. ft. (28 x 56) for a student union serving more than 2,000 meals mid-day.
General recommendations on area requirements
So far we have discussed the area requirements in very general terms, and shown how these requirements are affected by different factors. Some more definite recommendations on the size of kitchens must now be attempted. Clearly it is not possible to lay down exact measurements, but experience has shown that there are figures which can be used as a yardstick, provided that they are applied with discrimination. It is usual to take as a basic unit for fixing the size of a kitchen the number of square feet per meal served. A survey of existing kitchens shows that this figure varies from as little as 2 sq. ft. to as much as 7 sq. ft. or more. This figure includes the area for ancillary rooms as well as for the main kitchen. The higher limits refer to small kitchens and to larger kitchens where the provision is very generous; the lower figure usually applies to very large kitchens serving meals of a simple type, such as the large central kitchens found in the School Meals Service. 4-5 sq. ft. per meal served is a satisfactory figure to use as a yardstick, provided of course that the effects of all the various factors referred to above are borne in mind.
In “Residential Catering” areas are recommended for kitchens based on the total area “occupied by equipment and items of accommodation such as offices, stores and sanitary facilities together with access and circulation space”. It is stated that “the ratio between total kitchen area and the area occupied by equipment and accommodation varies from 3:1 in the case of small kitchens to 2.2:1 for large kitchens. Large kitchens therefore offer a considerable saving in total space.” An analysis of the areas recommended for kitchens illustrates this saving as shown by the following figures:
200 meals 7.0 sq. ft. per meal
500 meals 5.5 sq. ft. per meal
750 meals 4.1 sq. ft. per meal
The recommendation on total kitchen areas for schools in Bulletin 11 are less generous than any in the table given above. For kitchens planned to serve meals for 200 to 600 the unit area per meal lies between 31 sq. ft. and 3 sq. ft. It is claimed that a saving in gross area can be made by careful planning based on the suggestions made in the Bulletin and in particular by not having a separate servery. As stated in the document, these recommendations should certainly act as an incentive to architects when planning school kitchens to be “significantly more efficient and strikingly more economical in area than any that have preceded them.”
All the foregoing recommendations on space requirements are made with traditional types of equipment in mind. The areas provided must be adequate for the equipment used and for the staff who work in the kitchen. But they are not fixed and unalterable and clearly if new types of equipment become available either with increased output for the same dimensions or requiring less staff hours for operation, total areas could be reduced. Changes in food processing methods can also affect size as is the case in the kitchens described in Chapter 22 where all food is factory prepared and frozen and all dishes, plates and cutlery are “one use only”. Items of equipment already coming into use which contribute to a reduction in total kitchen area are the forced convection oven and the high speed cutter for vegetables and mixing operations. The garbage disposer and the can and bottle crusher also help by eliminating storage space if suitably located. Another development which will contribute towards a reduction in area is the development of matched module equipment such as that now coming forward from Lasmec, Moorwood Vulcan and Radiation. This type of equipment not only conserves space but also simplifies installation.
It is interesting to consider here the size of the dining room in relation to the kitchen. The yardstick used for assessing areas of dining rooms is a more exact and reliable one. This is because the factors which influence the size are not numerous and their effects can be more easily anticipated. Chief among them is the size and arrangement of the tables. The most economical use of floor space is obtained by using long rectangular tables placed in long rows or in individual units to seat 10 or 12. Where small tables seating 3, 4 or 5 are used, the space required per diner is greater. Limits range from about 8 sq. ft. for the former to about 12 sq. ft. for the latter, with 10 sq. ft. as a useful figure to use for guidance. On the basis of these figures it will be found that of the total floor area available for the kitchen and the dining room, one third should be allocated for the former, and two thirds for the latter. It is however not uncommon to use the dining room for more than one sitting, and in this case the kitchen and dining room would be about equal in size; with the smaller kitchens, however, the dining room will be rather smaller than the kitchen since the unit figure for dining remains constant whereas that for kitchens increases as the size of the kitchen diminishes.
It is interesting also to consider what proportion of the total area is allocated to the ancillary rooms in the kitchen. Here again the figures vary, but a good average for the space reserved for the stores, offices and cloaks, etc., is just under one third of the total kitchen area.
Finally, it must be clearly realized that all recommendations on area requirements given above are general and that when planning a particular kitchen the area must be carefully considered in relation to the known special requirements of the project. For this purpose it is essential that the person who will be running the kitchen should be consulted at an early stage. An interesting paper* by an American architect and addressed to dietitian caterers deals with this problem and shows how important it is that architects and caterers should get together to agree on exact requirements.