Climate has ever been a problem in the design of buildings, and its control a major factor governing architecture. The shape of buildings has been greatly influenced by the requirements of climate, because climate imposes limitations-the problem of designing buildings that are in harmony with the climate.
Though climatology may appear to be a new science, the architect has been a climatologist far longer than he may realize, because the architect throughout the ages has been exercising control over climate through orientation, site and town-planning devices, such as brise-soleil, tree-planting, wind-breaks, etc.
Before we go into the physics of the influence of sun, temperature, wind precipitation and humidity, it would be appropriate at the outset to clarify what is meant by “climate” and “architectural expression”.
The dictionary meaning of the word is, “the temperature and the meteorological conditions of a locality”. In the context of this paper, “climate” could be substituted with “macro-climate”, and “micro-climate”. Macro-climate denotes the general meteorological conditions of a region or country and accounts for the major phenomena of the region. “Micro-climate” denotes the meteorological conditions local only to a particular place, like the radiation, air currents at ground level, temperature, humidity and precipitation peculiar only to a limited area. It is the latter which architects have to encounter and intimately know, so that they do not compete against it, but go along with it and derive the best results from its beneficial qualities, and guard against the ravages of its undesirable qualities. It can be said to be the part of nature, that immediately surrounds a building and enters it, not just superficially but deep into its character.
Expression means “the act of expressing or stating; an outward reflection of feelings or thoughts; looks”. I think all these interpretations can apply in this context. The inner character of the building when successfully reflected in its outward appearance or looks can be construed to mean “architectural expression”. Buildings can have individual personalities and looks; given the same ground plan, two buildings can look very different from each other depending on how the plan has been developed, the treatment of the component members of the buildings, their specifications, etc. For example a simple rectangular plan could be a wood-framed building with a sloping roof deep overhanging eaves and open sides as in Malabar, or again, as in Morocco, a building with thick white plastered masonry walls, a flat roof and narrow slit openings. Thus two similar plans meant for similar use can be vastly different from each other.
History may provide some valuable lessons, and also explain these differences. It will reveal that the characteristic features of the architecture of any country were developed through special influences. Sir Bannister Fletcher gives prominence to six: (i) Geography, (ii) Geology, (iii) Climate, (iv) Religion, (v) Social customs and (vi) History.
A review of the history of architecture may provide illustrations which will indicate the major role of climate in developing architectural characteristics. The simultaneous influences of other factors, such as geographical and geological conditions, historical and artistic background, economy, technology and availability of materials, should also be taken into account, for often two places, with similar climate, may have different architectural expressions. But a careful analysis will reveal the fundamental characteristics, which will show surprising similarities.
It will be profitable to compare primitive dwellings such as an Eskimo igloo with an American wigwam and a Dyak house.
The Eskimo lives in a dreary waste-land of ice and snow. He invariably selects a sheltered spot for his habitation, which is constructed of ice and snow. Their igloos are grouped closely together, so that all could be in the shelter of some rocks or a ledge. The inside of an igloo is absolutely wind-proof, which is achieved by cementing the blocks of snow or ice by thawing them partly and permitting them to re-freeze with water poured over the joints. This and their oil-stoves manage to keep the family group comfortable. The Eskimo is particular about light, naturally due to a winter where only the reflected sky-glow provides light for a long time. He, therefore, fits thick panes of clear fresh-water ice, and these are again fused to the apertures by the method described above.
Several igloos serving various family functions are usually inter-related and connected to one another by internal passages; the one main entrance serves the entire unit, and is designed to act as a buffer against the wind and sleet. The entrance faces away from the prevailing wind but not on the lee-ward to avoid an accumulation of snow-drift.
The North American Indian has a dome-shaped wigwam, covered with borkslabs, rush mats or grass thatch, which have good weathering qualities. An aperture in the top of the domical structure controls the smoke, which can be intolerable if not removed from the interior. The aperture at the top has a flap which can be adjusted according to the shift of the wind. The doors are hung with mats which drop, shut and prevent the wind coming in.
The Dyaks of Sarawak, Northern Borneo, like the Sumatrans and other Polynesians, build community-houses on stilts-some a hundred feet long, divided into family apartments and common rooms. The house is made of pole-frames lashed together by ropes, with mud and reed or bamboo walls heavy down-pour of rain does little harm to the structure. The thatch provides a cool interior under the hot sun, and the platform on stilts permits a free circulation of air underneath, and being on an elevation enables the slightest breeze to be caught and directed inside. The stilted floor also ensures that floods, high-tides etc. do not inundate the interior; the houses are oriented to face the prevailing breezes. Thus it will be noticed that these primitive dwellings completely meet climatic needs and reflect them in their structures, detailing and siting.
The earliest evidence of climatic influence on architecture and town planning is found in Egypt. At Kahun, the streets sloped down to the middle, so that accumulation of rain-water may be quickly drained off.
Egypt has been said to have two seasons: spring and summer. The climate is warm; storm, fain, fog etc. are rare. The main characteristics of Egyptian architecture are the massive, unbroken expanses of walls, flat roofs of thick stone slabs, and colonnaded interiors, with inner courts. The scale was monumental, with battered walls, incised with reliefs and hieroglyphics.
The warm climate, free from storm and rain, with its brilliant sunshine was conducive to the simplicity of design, for as sufficient light penetrated the interiors through doors and small slits, there was no need for windows. Thus the unbroken massive walls not only protected the interior from the hot sun but also provided an unbroken surface which combine with the peculiar scope for sciagraphy encouraged ornamentation with incised reliefs.
In the interiors, the open courtyards with colonnades around them were sufficient shelter against the sun.
Babylon and Assyria
Babylon, between the rivers Tigris and Euphrates, was situated around the river deltas, a region of floods and swamps, besides torrential rainfall lasting for long periods. The summer was hot and humid, with swarms of troublesome insects. Therefore, elevated platforms on which to build towns and palaces were essential. Assyria, though nearer the mountains, had a similar climate, and, therefore, both Babylonian and Assyrian architectural styles are related.
The vast and imposing platforms, made of sun-dried bricks with wide ramp approaches from the plains beneath, the palaces with a series of courts were characteristic of this period, and in fact had a great influence on the planning of palace-complexes in many other countries. The heavy rainfall necessitated lining the brick masonry with an impervious surface covering, which used to be glazed brick tiles of many colours in Babylon. Slabs of alabaster, with bas-relief carvings were used in Assyria. These resulted in the characteristic surface decoration of these regions with colour mosaics or continuous carved panels depicting their exploits and achievements and which in turn have influenced other phases of architecture.
Persia, situated on a high table-land, has been described as a country of sunshine, gardens and deserts with a climate ranging between extremes of heat and cold. This accounts for the introduction of open-columned halls in their ancient palaces as at Susa and Persepolis-an influence that has crossed geographical barriers and been introduced in many other countries with similar climates.
The national love of beauty can be said to have been developed under the influence of the climate, affording as it did, a great scope for open-air life.
If climate has shown a marked influence on the architecture of Western Asia, it was in Greece that its influence was accepted as an architectural discipline. Town planning and orientation rules were strictly followed, and Greek philosophers had had written learned discourses on climatology. Xenophon had recorded notes on orientation, and Aristotle laid down rules about siting.
The Greek climate was moderate between vigorous cold and relaxing heat-hence the Greek temperament, combining the energy of the north with the lethargy of the south. The clear atmosphere and bright sunshine were largely conducive to the development of the precise and exact forms which are special attributes of Greek architecture. The climate favours an outdoor life, hence public functions like the administration of justice, dramatic performances, and public ceremonies took place in the open air. Porticos and colonnades which were important features served as shelters against the hot sun and sudden showers.
Vitruvius, described by Pierre Lavendan as the “forefather of modern town planning” had also recorded his ideas on the layout of towns and individual buildings according to various climatic influences, as far back as the 3rd century A.D. Vitruvius had influenced many thinkers, both of his day, and in later years, including Palladio. His following expression will prove that climatology was already an established science in his day: “For in one part, the earth is oppressed by the sun in its course; in another part the earth is far removed from it; in another it is affected by it at a moderate distance. Therefore, since in the sun’s course through the inclination of the Zodiac, the relation of heavens to earth is arranged by nature with varying effects, it appears that in like manner the arrangement of buildings would be guided by the kind of locality and the changes of climate. Towards the north, buildings, I think, should be vaulted, thoroughly shut in rather than exposed, and with an aspect to the warmer quarter. On the other hand, where the sun is violent in southern regions because they are oppressed by the heat, buildings should be open to the air with a northern, or north-eastern aspect. Thus we may remedy by art the harm that comes by chance. In other regions also, buildings are to be similarly adjusted to suit the relation of climate to latitude”.
At home, we find in Indian architecture evidence of highly developed science of climate control, which resulted in such characteristic features of Indian architecture as the chajja, jallis, deep rectangular piers, inner courtyards, etc. All the tricks in the bag- if I may use this expression, as I am sure my contemporary colleagues will also readily understand it-had been tried out. The louver, the brise-soleil, the sun-grill, patios, pools, convective cooling, etc. which are being re-imported to India at present, had been successfully and successively employed in all the phases of Indian architecture.
It could be possible for one to discuss, ad infinitum the architecture peculiar to the several different climate-regions throughout India, but as the scope of this paper does not permit an exhaustive examination, I think I will merely discuss one building in detail, which in my opinion, satisfies to the maximum extent all the aspects of climate-control, and in every other way is a worthy example of architecture.
Mahal-i-Khas, Fatehpur Sikri
Fatehpur Sikri is situated at a distance of 23 miles from Agra, and was constructed by Emperor Akbar, between 1569 and 1605 A.D. A sandstone ridge runs through the walled town from south-west to north-east, all the monumental or principal structures are built upon the ridge.
The climate of Fatehpur Sikri is similar to that of Agra, having an oppressive dry summer, with sultry hot monsoon period. The rainfall is moderate, averaging 30” to 35”, but the intensity is great, and some very heavy down-pours are possible. Also, owing to the geographical and topographical situation, it receives a few post-monsoon, and winter showers, accompanied by strong winds. The winter is sharp, though not severe.
Geologically, Fatehpur Sikri has an abundant stock of excellent building-stones, being actually situated on a site rich in sand-stone deposits. Very large pieces of stones, some even reaching 30’.0” length have been used. Lime is available nearby and other stones including white and coloured marbles are obtainable from Rajasthan.
The Mahal-i-Khas, or the principal palace in the complex composed of the Turkish Sultana’s house, Panch Mahal and the school consists of an oblong court 211’ X 153’ enclosed by wide and spacious cloisters, residences and the school. In the centre of the court is a large “hauz” or tank 95’ square, with steps leading down to the water, emerging from which is a platform 29’ square. Water was supplied to this directly from the water-works some distance away, through stone channels underground. The south façade consists of a range of buildings, surmounted by the Khwabgah, or the bed-room of the Emperor. This was connected by means of corridors with the Panch Mahal, Miriam Kothi, Jodh-bai’s Palace and the Turkish Sultana’s House. The main elevation is one-storey high, with the bed-room block above, but on the side facing the tank, its floor level drops to accommodate a low double-storeyed pavilion. The main chamber used as a dining-hall measures 27’ X 17’. The walls stand on a plinth and are hollow, closed on the outside by perpendicular stone-slabs.
Beneath the main structure of the Khwabgah is a chamber screened off from the pavilion by carved stone-grills. The chamber behind the dining-hall on the ground floor has sunk floors, connected by stone channels, with a raised dais, and it used to be filled with water during the hot months.
The Khwabgah is a small chamber 14’ X 14’ and must have been very exquisitely decorated. It is surrounded by a verandah 9”.6” wide with a lean-to roof of stone slabs. The roof of the room is flat externally, but covered internally. There are four doors with fan lights, closed on the outside by stone screens. The reveals are deep and hollow. There are embedded copper pipes which are said to have had connections with the boiler at ground level.
Having described this building, I will attempt an analysis of its suitability for climate-control.
As will be seen, the whole complex is grouped on the ridge, thus commanding the breezes, and the buildings are so terraced that those on the windward are lower than those on the leeward. Large courtyards are formed so that the breeze can still reach buildings further down-wind. All buildings are orientated north/south with their west walls blocked up. The main place has a north/south orientation and has a large tank on the north, in the direction of the breeze. Thus on a hot, oppressive day the wind could bear the evaporated humidity from the tank towards the deeply shaded pavilion causing convective cooling, at the same time humidifying the dry air. The south side, though deeply shaded had hollow walls, which enhanced their insulating quality. The roofs were covered with thick stone slabs and a covering of lime-mortar, with white rendering to further ensure that heat gains through radiation were not transmitted to the rooms below.
The bed-room on the first floor, shows a studied approach to both heating and isulation. The deep verandah all around ensures that during the summer the chamber is protected from the sun’s radiation. During the winter the doors would be kept shut, and ventilation effected through the hot-air pipes in the hollows of the walls.
The thick coved-roof affords the necessary insulation against radiated heat.
The structural details were conceived with a view to protect the materials from weathering and staining through the dripping of water. The chajjas and lean-to roofs have ridges and grooves, to simulate tiles, with a perforated cavesboard of stone, the perforations corresponding with the grooves. The wonderful state of preservation, with the stone work and carving looking as fresh today as when originally wrought, is enough proof of the efficacy of the detailing.
Whichever way one looks at it, the sense of security from the climate, and the atmosphere of being at ease are quite apparent. One cannot but marvel at the capability of the earlier architect to have so successfully applied their knowledge of climatology; no solution is involved and the directness of approach if emulated today would enrich our present-day architecture.
Thus far with the historical survey. An explanation of the physics of the influence of climate is necessary. The meteorological conditions that form the basis of climate are insolation, air, its currents and temperature, humidity, precipitation and rainfall. Actually, what makes for the difference is mainly the sun, the nucleus of the solar system.
The energy emanating from the sun is solar-radiation. Much of it is reflected back into space even before it reaches the earth or is absorbed by the atmosphere. About one-third of the sun’s radiation reaches the earth’s surface and is transformed into other forms of energy-heat through conduction. Convection and radiation, evaporation and reflection from the ground.
The total insolation at any place depends on the position of the sun according to the time of the day and the season, presence of clouds and other obstruction, direction and angle of slope of the staion, its latitude and its surroundings.
Sunlight is necessary in buildings, because: (i) there is an evident desire for it as it has a psychological effect on well-being, (ii) it is a powerful bactericidal agent, (iii) it has specific curative effect in certain illnesses and a stimulant to a person’s resistance to illness, (iv) it is essential for the growth of living bodies, (v) it facilitates ventilation by causing convective currents, and (vi) it can be used as a source of heat.
Thus, it will be seen that sunlight is an important factor, not only in a biological manner, but also because the other elements of climate are in turn dependent on it and influenced by it.
It would be difficult for man to cause any modification in the macro-climate of a place, but it is possible to modify its micro-climate. It is important then to know how much of solar radiation is best suited for the particular place. If it is situated in a latitude far north or south, it would be necessary to avail of as much solar radiation as is possible; on the other hand in the tropics, it would be necessary to intercept most of the solar radiation, not only in buildings, and its immediate surroundings, but also in the town-plan and its region-plan.
This can be done by proper siting with regard to features like hills, mountain slopes, snow-slopes, lakes or sea, etc. It has been found that reflection from sea, lakes, snow-slopes, etc. considerably increase the temperature of a place. Without going into any further detail, I would state that the correct location of a town in regard to climatic data is half the battle won in ensuring comfortable living conditions.
Study of insolation is necessary because the architect, with a knowledge of these principles, can, among other things, select a site suiting his requirements, and select suitable slopes for roofs, walls and other surfaces, according to whether he desires more or less heat from solar sources at given times of the year.
In underheated areas the problem is merely to position the building so as to utilize all available sunlight. It is in overheated areas or seasons that the architect has to solve the problem of keeping excessive sunlight out.
Several methods and gadgets are available to the architect for determining the sun’s positions and amount of light coming in. The simplest is the Burnett System which consists of two diagrams. The first shows graphically the position of the sun on a plan at different times of the day and the months of the year, and the second shows the altitude of the sun. The diagrams are used beneath tracing paper, and are thus direct and easy. Used together, they show whether or not sunlight will penetrate a given opening. Conversely, it can also be found out as to what amount of obstruction in the shape of horizontal sun-shades or vertical baffles will be needed to stop the penetration of sunlight at any season. So far as this author knows, Burnett diagrams have been prepared in India only for Delhi, Chandigarh, Bombay and Madras. It would be very useful if the National Building Research Station, Roorkee, undertook to make diagrams for every latitude in India, or at least for every alternate latitude. Equipped with such a set, the architect can easily determine the exact projections, and the best locations of sun-shades and louvers necessary for his purpose. There are other various methods too, like the solar shadow trace diagram, the Soldiagram, the Heliodom, the Little Sundial, the Solarascope, etc. The Building Research Station had exhibited at the India 1958 Exhibition, a solarascope for Delhi. With methods such as these, shadow patterns, shade and sunlight penetration could be easily studied with the help of models of the building. A very effective and natural method of controlling radiation is the planting of trees and creepers to act as screens. This inexpensive and pleasant method should be considered, for example, to block the glare of the low western sun. Screens of shade trees or living screens of flowering creepers, besides their shadow and effect, also affect the micro-climate by their CO2/oxygen exchange, and their absorption of heat rays of the sun. The purpose of my dwelling at length on the control of sunlight in buildings, either in admitting or excluding it, is to stress that to a large degree sun orientation is the most crucial step in climate-conditioning of a building.
Temperature is the degree of heat of a place, and depends on the radiation, latitude of the place, its height and surroundings.
A study of the diurnal cycle of temperatures for the year would reveal useful information. For example, it could be noticed that the coolest time of any twenty-four hour period, on the average occurs sometime during the night. Therefore, to keep a house cool during the hot months, one should open the windows only in the hours of darkness and close them at sunrise.
This naturally leads us to the question of insulation. A great difference in the external temperature and the room-temperature of a well-insulated building is possible sometimes as great as 12 to 15 degrees F. Double-roof, water-insulated roof, hollow slab roof, roofs with insulating layers, hollow walls, insulating linings under the ceilings, or in walls, are quite the most common applications.
Painting, either light or dark according to its needs, is also very useful.
A knowledge of these temperature data opens the avenue to exploit the possibilities of control, as it would suggest to the architect as to where insulation is necessary and what type best suited.
Wind and Humidity
These are related phenomena with temperature, and play a vital role in causing physical comfort or discomfort. At high temperatures moist breeze creates comfort conditions, whereas dry breeze cause more discomfort. This would suggest itself to the architect, as to when passage of air currents are necessary. For good ventilation in tropical climates, not only must rooms as nearly as possible face the breeze, but the shape of the rooms and the relative size and position of the doors and windows have to be correct. It is important that there should be ventilation fairly near the ceiling, high up in the walls, or actually in the ceiling to let the heated air escape. The side of the building facing the breeze needs to have more window area, and preferably low in the wall, than the other side, to avoid the creation of draughts by suction.
Mention must be made here of the effective way in which pools can condition the micro-climate of a place. Patios, gardens and other plantings can either encourage thermal currents or block strong winds, depending on their placing, and these simple methods deserve more attention from architects.
Data about the velocity, temperature, humidity and direction of air currents should be known so that the architect may benefit from its study. Usually, it is easy to collect these data from the meteorological laboratory.
The intensity of rainfall of a place strongly influences its architecture, for dependent on that the architect decides on the most suitable slopes for the roofs of his buildings, the overhang, the method of storm water disposal both from the roof and from the ground, the arrangement and placing and size of windows etc.
If the physics of climatology are understood, a solution to counteract each undesirable phenomenon, and a method to benefit from its good qualities can easily be arrived at. In a specific climatic condition, the reaction to it is bound to be similar, if not the same, over several applications; and hence the making of a style or characteristic. This is specific only of a particular area and if these characteristics are grafted to another area the result is bound to be incongruous. These characteristics, then, are a result, or a derivation from the needs of climate-control. If, therefore, a building has to successfully express the effect of its climate, it is necessary for the architect to analyse all the basic climatic conditions, utilize the data available and arrive at independent deductions that meet the basic problem in a systematic manner, in just the same way as he would determine the stresses in the different members of its structure, instead of being just guided by feeling or superficial observation.
In India a fine heritage exists; but it is unfortunate that we have in recent years not taken inspiration from it. We have lost sight of the importance of climate in architecture?
Jeffrey Aronin who finds a similar situation in U.S.A. proffers an answer in his book “Climate and Architecture”. “Because of increased travel among the nations, people have borrowed one another’s styles without properly considering their function or climatic suitability in the new position”. It appears true of India also. I would also consider that an unintelligent copy of clichés in current fashion, a careless adoption of superficial details of climate-control that must have had careful analysis and examination elsewhere before their adaptation, are also prime causes.
The architecture of Dudok, for example, deriving its inspiration from space and influenced by contemporary art, and interpreted to satisfy the climatic needs of Holland, cannot yield the same satisfactory results if copied unintelligently by immature architects in India. A careless application of details of weather-control methods tried, perfected, and used, say in Brazil or Mexico, cannot be as successful if their principles are eschewed.
One often wonders at the surprising degree of efficiency in the control of thermal effects in our rural houses, though they fail in many other ways. These mud and thatch houses are good examples of directness in approach in solving a problem, their design being free from preoccupations or distractions from cliches.
In conclusion I would venture to state that a scientific and objective approach to the problem of climate-control, tempered by artistic institution, is necessary to add that quality to our buildings that would, in spite of the equating effects of modern technology and international economy, brand our architecture “Indian”.