Building Dimensions -- Fitting Buildings to People

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Fig 4-16

The dimensions of a building grow ultimately from the dimensions of the human figure. At the most basic level, a woman sitting in a soft chair establishes certain important dimensions (ill. 4-16, right). The interior of the chair must be large enough in all dimensions to support her body comfortably in any of a number of normal sitting postures: feet on the floor, legs crossed, legs tucked under her body, sitting straight up, sitting wedged diagonally into a corner of the chair, even sitting with a leg dangling over one armrest. The distance between the seat cushion and the floor, the angle of the cushion, the angle of the chair back, and the height and angle of the armrests all are based on the size and configuration of the average human body, represented here by a woman. The external dimensions of the chair grow from these dimensions, plus the thickness of structure required to support the weight of her body and the thickness of padding required to distribute her weight comfortably across her flesh. Around the chair, within easy reaching radius of the woman’s arms, are other furnishings: a lamp tall enough to cast light over her shoulder and onto her book; a magazine rack large enough to contain ordinary reading matter, which in turn is of a size that comfortably fits her hand and eye; and a side table at a height that puts a cup of tea within easy reach (ill. 5-16, below).

ill. 5-16

The woman rises and walks to the dining table. As she moves, her body sweeps a volume of space that must be maintained clear of obstructions. There must be space for her to move behind her dining chair, space to pull out the chair, and space to enter between her chair and the next (ill. 6-16, below). The chair must support her comfortably at a height appropriate for eating, and the table must present the table ware and food at a height convenient to her hands and mouth. The plates and cups are of sizes that will serve the quantities of various foods that her stomach is expected to hold. The utensils are fitted dimensionally to her hand and mouth. The dimensions of the tabletop are worked out so as to accommodate a given number of diners, together with their tableware, elbows, and knees. it's also worked out to maintain a comfortable distance between people sitting opposite each other (ill. 7-16). Even when people are sifting or standing with no table between them, they keep distances that allow sufficiently close visual and aural contact without encroachment on personal spatial territories. A dining table or a living room can be too small for com fort, thrusting people into intolerable proximity. It can also be too large, making communication difficult.

Fig 16-6
ill. 6-16

ill. 7-16

Rooms acquire their dimensions on the basis of such considerations: the dimensions and forms of human bodies, the dimensions and forms of the necessary pieces of furniture, the dimensions and forms of the volumes swept by moving human bodies, and the desired distances between people (ill. 8-16 below). Even a television set has its appropriate distance from its viewer.

ill. 8-16

In a kitchen, bathroom, or factory, machines acquire at least equal status with people in determining spatial requirements. The machines are arranged in a convenient sequence. Each has its own dimensions: the dimensions swept by its working parts or moving workpieces and the dimensions swept by the moving bodies of its operator and its maintainers. The room must provide amply for all these volumes and furnish other volumes to conduct pipes, hoses, wires, or ducts to and from the machinery as required.

Some very simple sorts of mechanisms that are universal in buildings also demand space for their operation. Sliding drawers and swinging doors are two major examples in which both the operator and the mechanism must have space to move freely.

In general, the larger a building is, the more it will cost to build. Consequently, we usually attempt to make rooms as small as is consistent with comfort. By relegating specific activities and pieces of furniture to specific places, we can often create a workable room within remarkably small dimensions. But a compact, carefully worked-out room arrangement has little or no flexibility. Any change in furniture locations would require enlarging the room. This is a choice that designers constantly face: a larger room allows for more subsequent choice and variety in its furnishings, but a smaller room is generally less costly.

The height of an ordinary room is determined, at minimum, by the height of the tallest person normally expected to move through the room, plus a bit to allow for his hat and a small safety factor (ill. 9-16 below). But there is much more to it than this. A ceiling may be high enough to clear the hat but still feel uncomfortably low and oppressive, particularly if the room is large in horizontal extent. In general, the larger the room is, the higher the minimum height of a ceiling must be so as not to appear to bear down on the occupant. Ceiling height has important effects on air convection and the propagation of natural light; these factors also tend to indicate higher ceilings for larger rooms. Primitive houses in sub-arctic regions are commonly built with very low ceilings, both to minimize heat losses to the outdoors and give a snug, cozy feeling during the cold winters. In warm climates, high ceilings allow warm air to drift to the ceiling and comfortably cooler air to pool closer to the floor, where the occupants are. In churches, concert halls, and sports arenas, high ceilings allow clear lines of sight from all spectators to the performance and achieve a better distribution and reverberation of sound. The heads of ordinary windows are usually placed at least high enough that a standing person can see comfortably to the horizon (ill. 10-16 below). Where natural light is important, windows often are placed as close to the ceiling as possible, allowing only for the necessary lintel to support the wall and floor above. Sill heights of windows are much more variable. For ordinary purposes, it may be sufficient that the window reach low enough that one can look out from a sitting position, or perhaps a bit higher so that one can lean out the window while resting one’s forearms on the sill. It often is important that a table, chair, or countertop fit against the wall beneath a window. In a room high above the ground, a higher sill may offer a welcome feeling of security against tumbling out. In a private room at ground level, a very high sill keeps out prying eyes. In a window opening onto a garden, a sill set into the floor allows one to walk directly outside in pleasant weather.

ill. 9-16

ill. 10-16

In the absence of other factors, the perimeter of a building is shaped by the outermost walls of the most convenient internal aggregation of rooms. When combining rooms, certain proximities are important to maintain. A bedroom should be near a bathroom, without an intervening bedroom or living room. The kitchen should be near the dining room. Such simple relationships are basic to the design of any building.

Doorways are necessary to allow access to and from rooms. They are scaled to accommodate a walking figure, plus a bit more to allow for carrying a bundle of groceries, a suitcase, or a young child (ill. 11-16 below). 1 public buildings, doorways become exitways whose capacity must be calculated to pass the entire occupant population of the building in a specified

ill. 11-16

Corridors are useful for facilitating complex circulation paths among a number of interrelated rooms. A corridor width of 3 feet (900 mm) is sufficient for a single person, but two people will find it difficult to pass one another. Another foot (300 mm) of width makes passing easy for two individuals but will not permit the comfortable passage of two parallel files of people. Corridors must be sized like water pipes, to accommodate the expected flow. The pipelike character of many unimaginatively designed corridors has led many designers to do away with them, substituting instead a seemingly generous lounge or lobby. Unfortunately, the result is usually little more than a broader corridor, with circulation paths cutting across in all directions, leaving little room free for other activities (ill. 12-16). Such situations are easily foreseen by sketching on a floor plan the natural paths along which people will circulate.

ill. 12-16: Natural paths through a lobby.

There is no fully satisfactory answer to this dilemma. The best we can do in most cases is to size building components to accommodate the preponderance of the adult population while leaving a few people of exceptional size or shape, along with the younger children, in the position of continually having to make accommodations to the building. Much of their strain can be eased through the provision of appropriately scaled furnishings, as seen especially vividly in the case of children. in residences, libraries, lounges, and other buildings in which the inhabitants are free to locate themselves in any of a number of places, spaces of varying scales and degrees of enclosure may furnish important opportunities for persons of different physical and psychic dimensions to find appropriate surroundings.

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