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Part 1. Man, Natural Environment, and Architecture
1. Environment and Architecture
2. Architectural Thermodynamics and Human Comfort in Hot Climates
1. Environment and Architecture
Effect of Climate on Architectural Form
Conscious Modification of the Microclimate
Trends in International Architecture
When an engineer designs a machine, a bridge, or a regulator, each line in his drawings is the result of a great accumulation of laws and principles from a dozen different mechanical sciences. He designs the machine to withstand a certain amount of strain and to do a particular job. In both these aspects he must consider and apply all that he has been taught in such fields as physics, dynamics, structural mechanics, and the resistance of materials, and must put into each line a whole library of expertise.
Similarly, when an architect designs a town or a building, every line is determined by the application of the same complex set of mechanical laws, with the addition of a whole collection of other sciences whose provinces are less well defined: the sciences that concern man in his environment and society. These sciences-sociology, economics, climatology, theory of architecture, aesthetics, and the study of culture in general-are no less important to the architect than are the mechanical sciences, for they are directly concerned with man, and it is for man that architecture exists.
The mechanical side of an architect's work-ensuring that his building will stand and provide protection against the elements, or that the street pattern of a town performs its function efficiently-is no more than a preliminary to his real creation. Only when he has provided these mechanical prerequisites, which should be incorporated without question or argument, can he begin to consider the real problem of designing a building. He is rather like the pianist who can start to interpret the music he plays only after he has mastered the technique of piano playing.
A machine is independent of its environment. It is little affected by climate and not at all by society. A person, however, is a member of a living organism that constantly reacts to its environment, changing it and being changed by it.
A plant provides a good example of the mutual interaction between a living organism and its environment. It possesses its own heat and water economies. Its respiratory heat is the result of metabolism which tends to raise its temperature, just as with animals. It perspires, and the evaporation of this perspiration leads to cooling, since every gram of water given off requires between 570 and 601) calories from the plant, depending on the air temperature. Consequently, plants exert a reaction on the microclimate of their environment and to some extent adjust their own temperature to their particular needs.
In the same way, a building is affected by its environment. The climate of the locality and the buildings around it mold the building, so that, even though social, cultural, and economic aspects are important, it owes much of its shape to these factors.
Effect of Climate on Architectural Form
Climate, in particular, produces certain easily observed effects on architectural forms. For example, the proportion of window area to wall area becomes less as one moves toward the equator. In warm areas, people shun the glare and heat of the sun, as demonstrated by the decreasing size of the windows. In the subtropical and tropical zones, more distinctive changes in architectural form occur to meet the problems caused by excessive heat. In Egypt, Iraq, India, and Pakistan, deep loggias, projecting balconies, and overhangs casting long shadows on the walls of buildings are found. Wooden or marble lattices fill large openings to subdue the glare of the sun while permitting the breeze to pass through. Such arrangements characterize the architecture of hot zones, and evoke comfort as well as aesthetic satisfaction with the visible endeavors of man to protect himself against the excessive heat. Today a great variety of devices such as sun-breakers or brise-soleil have been added to the vocabulary of architectural features in these zones.
Notice, too, how the gabled roof decreases in pitch as the rate of precipitation decreases. In Northern Europe and most districts subjected to heavy snow, gables are steep, while in the sunnier lands of the south, the pitch steadily decreases. In the hot countries of the North African coast the roofs become quite flat, in some areas providing a comfortable place to sleep. Still further south, in the tropical rainfall zone, the roofs are again steep to provide protection from the torrential downpours typical of the region.
It is worth noting that so long as the people of the humid tropical regions built their huts with reeds and grass, which allowed air to pass through the walls, the steeply pitched roof was a useful device. However, once they began to use more sophisticated materials like cement block and the common gabled roof topped with corrugated iron sheets, the houses became unbearably hot and stuffy. This kind of roof prevents the catching of draughts at the very level where they prevail, and the solid walls prevent the passage of air.
The traditional flat roof and the brise-soleil of recent tropical architecture, with its modern feel, have attracted the imagination of architects in colder regions who are continuously searching for something different and exotic. The result is that in some northern cities thoroughly inappropriate examples of architecture, with shapes suitable to an alien climate, have succeeded in making the neighboring buildings look old-fashioned without responding to the needs of the people in their climate. The temptation to create up-to-date designs which assails a modern architect prevents him from achieving the chief aim of architecture: to be functional. He forgets the environment into which he will implant his buildings because he is attracted by new and modern innovations and gadgetry. He fails to realize that form has meaning only within the context of its environment.
The techniques and equipment available to the architect today free him from nearly all material constraints. He has the run of centuries of styles and can choose his plans from every continent on earth. But he must remember that he is not building in a vacuum and placing his houses in empty space, as mere plans on a blank sheet of paper. He is introducing a new element into an environment that has existed in equilibrium for a very long time. He has responsibilities to what surrounds the site, and, if he shirks this responsibility and does violence to the environment by building without reference to it, he is committing a crime against architecture and civilization.
What constitutes the environment of a building? Briefly, it is all that surrounds the site on that part of the Earth, including the landscape, be it desert, valley, mountain, forest, seaside, or riverside, and what is above the surface with its seven zones that envelop the Earth and influence terrestial life. The zone most concerned here is the first, the atmosphere. This zone rises to an average height of 10 kilometers and reaches 20 kilometers in the Tropics. It contains the humidity on which human, animal, and plant life depend. In the six zones above the atmosphere, oxygen, ozone, and hydrogen are present in different concentrations that affect the cosmic radiation reaching the surface of the earth. In the natural order prevailing in the environment, there has always existed a continuous balanced flow of cosmic radiation within which all living organisms and even minerals have been created and evolved.
Some materials are transparent and some are opaque to the various components of this radiation. Man should be careful not to disturb the natural electromagnetic balance by improperly selecting the material he uses for his dwelling. Thus wood is a more desirable material for man's surroundings than reinforced concrete. Aesthetically, man appears to prefer wood within his dwelling in the form of furniture and structural elements, which he often describes as warm, contrary to steel or other metals, which he describes as cold. This psychological effect can be explained in part scientifically by the physical properties of both materials, including their heat conductivities and insulation characteristics.
These details demonstrate that the architect has a moral responsibility to consider whatever may affect the efficiency of the building and the well-being of the people whom he is housing. Besides the tangible and measurable features of the environment, there exist intangible elements, but insufficient scientific information prevents their use in town planning and architectural design. Therefore, this discussion is limited to the tangible and measurable elements of the environment, mainly the climate.
The importance of climate is clear. All living organisms depend entirely on climate for their existence and adapt themselves to this environmental influence. Plants that live in the Tropics cannot live in the Arctic, nor can arctic plants live in the Tropics, unless of course the immediate local conditions-the microclimate-are arctic, as at the top of a high equatorial mountain. Most organisms, in fact, are limited to a habitat of narrow climatic range.
Conscious Modification of the Microclimate
Yet not all species are so limited. Many animals can regulate their own internal body temperature and can maintain it at a constant value even during considerable fluctuations of the air temperature. Man has an elaborate and very sensitive mechanism involving the secretion of sweat and the distribution of blood that keeps him at about 37 °C at all times. In general, warm-blooded animals can survive wider variations than coldblooded ones. Some species manipulate their environment to produce a favorable microclimate: the tortoise does so when it hibernates for the winter. Man, too, does this in a variety of ways. He can change his microclimate by changing his clothes, building a house, burning fuel, planting trees, digging artificial lakes, and using machines to heat, cool, moisten, or dry the air around him.
A principal purpose of building is to change the microclimate. Early men built houses to keep out the elements-rain, wind, sun, and snow. Their purpose was to produce an environment favorable to their comfort and even to their survival. The microclimate on each building site is changed into several different microclimates as the result of the construction of the house itself. The microclimate adjacent to the south wall is quite different from that at the north wall, and the climates at the east and west walls are again different. Inside the building, each room has its own microclimate which is a modification of one or more of the outdoor microclimates.
Before the advent of the industrial era and mechanization, man depended on natural sources of energy and available local materials in forming his habitat according to his physiological needs. Over many centuries, people everywhere appear to have learned to interact with their climate. Climate shapes the rhythm of their lives as well as their habitat and clothes. Thus, they build houses that are more or less satisfactory in providing them with the microclimate that they need. In the warm humid lands of East Asia, the local inhabitants live in huts with flimsy, loosely woven walls that allow the slightest breeze to pass through. The people who live under the blazing sun of the desert construct houses with thick walls to insulate themselves from the heat, and with very small openings to keep out hot air and the glare of the sun.
These successful solutions to the problems of climate did not result from deliberate scientific reasoning. They grew out of countless experiments and accidents and the experience of generations of builders who continued to use what worked and rejected what did not. They were passed on in the form of traditional, rigid, and apparently arbitrary rules for selecting sites, orienting the building, and choosing the materials, building method, and design.
In any approach prescribed by tradition, it is essential that every injunction of the tradition be strictly observed. Thus, if one element were changed in a traditional building method, that change, though small, could destroy the entire validity of the building as a satisfactory solution to the local climatic problems. In this sense, both the material and the way it is used are very important. For example, if mat screens are replaced by corrugated iron or some other solid wall material, then even though the building may appear more substantial, the lack of ventilation could make the interior intolerably hot and stuffy. Modern architects have attempted to solve this problem with modern technology, for instance, introducing the vented screen-wall, using unshaded concrete or brick claustra-work to replace the objectionable solid wall. Many different examples of this can be seen in entire elevations of modern buildings in tropical zones. While such a solution is a definite improvement over the solid wall, careful investigation reveals that it is not as efficient as the humble mat screen. When the sun-breaking or brisesoleil elements of the claustra-work are not shaded, they heat up and then transmit this heat to the air flowing into the building through the claustrawork, as well as reflecting warming solar radiation into the interior.
Every substance that has formed part of a living organism will retain some of its original qualities of climatic response as long as its original structure is not destroyed or significantly modified. Wood, hair, grass, leaves, reeds, cotton, hemp, and other organic materials are sensitive to air humidity. When increased ventilation and humidity are required, matting responds to its climate by absorbing moisture from the air passing through it into the building, thereby reducing the degree of humidity in the room. In contrast, claustra-screen walls can breathe, but they do not perspire. A mat, being porous, is a poor heat conductor, and cools to below air temperature by evaporating the moisture it has captured from the air. Thus it cools the air passing through it. Furthermore, a closely woven mat with loose fibers and bristles around the ropes will intercept dust as well.
Trends in International Architecture
Changing a single item in a traditional building method will not ensure an improved response to the environment, or even an equally satisfactory one. Yet change is inevitable, and new forms and materials will be used, as has been the case throughout history. Often the convenience of modern forms and materials makes their use attractive in the short term. In the eagerness to become modern, many people in the Tropics have abandoned their traditional age-old solutions to the problems presented by the local climate and instead have adopted what is commonly labeled "international architecture," based on the use of high-technology materials such as the reinforced-concrete frame and the glass wall. But a 3 x 3-m glass wall in a building exposed to solar radiation on a warm, clear tropical day will let in approximately 2000 kilocalories per hour. To maintain the microclimate of a building thus exposed within the human comfort zone, two tons of refrigeration capacity are required. Any architect who makes a solar furnance of his building and compensates for this by installing a huge cooling machine is approaching the problem inappropriately and we can measure the inappropriateness of his attempted solution by the excess number of kilocalories he uselessly introduces into the building. Furthermore, the vast majority of the inhabitants of the Tropics are industrially underdeveloped and cannot afford the luxury of high-technology building materials or energy-intensive systems for cooling. Although traditional architecture is always evolving and will continue to absorb new materials and design concepts, the effects of any substitute material or form should be evaluated before it is adopted. Failure to do so can only result in the loss of the very concepts that made the traditional techniques appropriate.
Only a scientific approach to the evaluation of such new developments can save the architecture of the Tropics and Subtropics. The thoughtless application of modern methods in this region is seldom successful. A thorough understanding of the climatic environment and developments based thereon is essential for appropriate solutions. Although traditional architecture was evolved intuitively over long periods, it was based primarily on scientifically valid concepts. The modern academic world of architecture does not emphasize the value of investigating and applying concepts scientifically and, therefore, has no respect for vernacular architecture. Now is the time to bridge the gap between these widely different approaches.
All traditional solutions should be evaluated scientifically before they are discarded or substitutes proposed. The phenomena of the microclimate must be analyzed and new building materials, methods, and designs must be tested until the complex relationships among buildings, microclimate, and human beings are fully understood. Fortunately, agriculture is perhaps even more intimately affected by the microclimate than architecture, and agricultural scientists have long made careful observations of the climate near the ground and in small localities. Their findings are available to those interested in tropical and subtropical architecture.
Another science to which architecture is indebted is aerodynamics. The methods of investigating airflow around the wings and bodies of aircraft are now being used to study airflow through, over, and around buildings. Scaled and full-size models can be tested in wind tunnels to determine the effect of the size, location, and arrangement of openings on the airflow through individual buildings, as well as the nature of wind patterns and forces between groups of buildings.
Today more attention is being given to the relationship between climate and architecture, and several building research organizations are beginning to examine this relationship.
Various disciplines, including aerodynamics and meteorology, provide an impressive stock of facts that are extremely useful to architecture. The architect is responsible for interpreting these facts and applying them to his designs. In this respect, he resembles the attending physician, who, though using the expertise of the physiologist, radiologist, or bacteriologist, is the only person who can actually undertake the treatment of a case.
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