Climate is one of the important factors which affects architecture. It is not very satisfactory to make an exclusive study of climate in relation to architecture because architecture is a complex product where, in addition to climate, materials, modes of construction, religious, political and social conditions have all played their part. We can, therefore, review the subject in a general way.

In architecture climate influences planning, structure, type of roof and external treatment:

(a) Climates vary from cold to hot. Very broadly cold denotes compact and enclosed planning. Heat demands openness.

(b) Cold and extremes of heat encourage thick and massive structures. Tempe­rate conditions permit use of light structures.

(c) The rain and the snow dictate the shape of the roof.

(d) The am of sunshine, winds, clouds and humidity guide the treatment of openings and their locations.

Let us see whether and how these broad climatic factors were expressed in the architecture of the past.

(a) Egypt with its brilliant sunshine and heat and absence of rains gave pyramids, massive and windowless walls with thick flat roof.

(b) Babylon, Syria and Mesopotamia with their damp and low-lying plains fu of swamps, fl and torrential rains gave buildings elevated platforms approached by broad stair-ways and ramps.

(c) Persia with its dry and hot climate gave open columned halls. Persian influence was also apparent on Asian countries because of the political influence of Islam.

(d) Greece with less rigorous climate, but occasional hot sun and sudden shower gave porticoes and colonnades.

(e) Romans took inspiration from Greece and as the climate of Italy had nothing special to cater, the Romans also had porticoes and colonnades.

(f) The climate of France varies from temperate to sub-tropical, from north to south. The variation regulates the size of door and window openings which become small in south. The pitch of roofs, steep in the north, to throw off snow, becomes almost flat in the south. The other European countries later came under the sway of classic and Christian influences.

(g) In India traditional climatic features arc courtyards, verandahs and balconies, chhajjas, perforated jallis and pools and fountains.

These broad features were appropriate and useful in the past but now with the advance in technology and research, a variety of solutions have been found for climatic problems. It is necessary that we study them while we consider a National Policy of Architectural Expression instead of being satisfied with the idea that whatever we have done in the past in the solution of climatic problems was best and those solutions would hold good for all times.

Let us take the problem of climate subjectively first and then study it objectively with the requirements of our country.

Climate is determined mainly by solar heat and glare, prevailing winds and humidity and rain. In architecture these climatological factors should be so dealt as to produce a physically and psychologically comfortable structure for residence, work or recreation. It is not just enough to take their advantages or minimise their disadvantages as was done in the past.

Sun is the most important factor in climate. Its radiation decides diurnal temperatures. The temperature is raised directly by the penetration of the sun’s rays through openings and indirectly through the absorption and radiation of heat by the walling and roofing materials. For comfort both the factors should be considered. Measures adopted to shield direct penetration of the sun’s rays through openings would not be useful if the adjacent walls and roofs do not have sufficient insulation value. Roof is the most affected part of the structure because it receives sun’s rays throughout the day.

(a) The easiest method of ensuring conditions of comforts with regard to sun factor is to avoid aspects which give maximum temperature due to direct rays and to provide an envelope of shade over the maximum of structure if the direct rays cannot be avoided. The faces of a building can also be shielded from direct rays by brise-soleil or sun-breakers. One of the methods for protecting top of a building is to have a breathing-roof—a roof laid in two layers with a gap and through ventilation.

(b) The sunshine, though unwelcome in summer, may be welcome in winter. In such conditions, the measures of shielding and the selection of aspect require comparative study.

(c) Protection against glare is also very important. Measures taken against the sun’s radiation do not necessarily reduce the glare. The factors producing glare are the bright sky and the surrounding areas. These factors affect  all the sides irrepective of the sun’s radiation which may vary and which may be practically absent on one side (north in some places). Glare may be reduced by screens, venetians or by plantations and colour treatment to the sources of glare.

Prevailing winds are useful for natural ventilation and for combating discomfort due to humidity. Strong hot and cold winds are to be avoided.

(a) For comfort it is essential that partial or through ventilation is provided by taking advantage of prevailing winds. Where there is extreme heat in summer and where it is necessary to close openings to avoid heat and glare, it would be an advantage to plan buildings to facing the winds of the humid months instead of average prevailing wind which may be from some other direction. For comfort it is also necessary that air movement should occur in a building at the level of occupancy and use.

(b) Where there are rows of buildings “wind eddies” are produced on the lee­ ward side. The field of eddies is determined by the height. length and width of building blocks. Prevailing winds become weak and indefinite in the field of eddies and cannot produce natural ventilation in building located in such areas.

(c) It is not necessary to face the buildings directly into prevailing winds because their velocity is not reduced considerably by facing the building away even upto 60°.

(d) The meteorological data gives winds at a height varying from 30’ to 60’ above ground level. So far such data was collected for the use of avia­tion and cannot be blindly used for buildings. The air velocities arc reduced considerably at lower levels. The winds are also likely to be deflected by obstructions such as rows of buildings and trees. Even the positions of trees, hedges and shrubs are likely to affect them by producing wind eddies.

Rain has ceased to be a decisive factor with regard to the shape of roof, because rain water can be easily disposed of even from a flat roof. Direction of the rain is generally the same as that of prevailing wind. Therefore, in areas having considerable rains, measures for protection against its penetration into building are required.

It would be useful to see how the country has reacted to the above recent trends for dealing climatological factors. Sun-breakers and screens have already appeared and that shows that we are on the move. We must see that the move is in the right direction and does not end in ignorant imitations or gymnastics in aesthetics or surface treatment. This trend is also apparent and requires a check. If we are to foster progressive architecture and right type of architectural expression, the country should undertake research and make available scientific data and knowledge about climatological factors and their treatment in relation to structures and enclosed space. N.B.O. has begun giving climatic data but that is not enough. We should have some comprehensive study on the lines of “Climatological Study with Architectural Recommendations and Town Planning Considerations for the Delhi Region” by Albert Mayer and others. It would be far better if our own men are encouraged and financed to undertake such studies. Individuals and voluntary groups cannot afford to do this. The country and profession should not expect them to do so.

Climatic conditions affect structures and enclosed space in our country can be very broadly _classified into three varieties.

(i) Hot and dry
(ii) Warm and humid
(iii) Cold of the hill.

(a) The main problem of the hot and dry region is to keep out the day time heat or the solar radiation. Past methods of shading the opening with chajjas, thick walls with small openings, more heights and verandahs are not always adequate—shading the walls and openings do not necessarily create comfort. The most effective method is the right orientation. More heights do not give more natural ventilation although they may give more volume of air in a room. The ventilation depends on air in­take per minute and the number of air changes per hour rather than on the volume of a room. Verandahs on the east and west do not protect back walls against heat because of the general low altitude of sun on those two sides. For sleeping purposes also verandahs are not always satisfactory because of the radiation given out at night by their floors and the surrounding masonry.  Courtyards offer some physical and psychological advantages than verandahs provided they are shaded during day and landscaped properly.

(b) The main problem of warm and humid region is to provide the maximum of natural ventilation to counteract discomfort of humidity. It is simple to increase humidity but it is not at all possible to reduce it by any econo­mical method. The best solution is, therefore, to make maximum use or prevailing winds. Glare is also generally present in this region. Screens and jallis are more effective as they do not only screen bright sky, but also allow cool breezes to pass through them.

(c) The problem of the hills are that during summer if the sun’s radiation is excessive, there should be some shading during day but at night, both in summer and winter, cold air should be shut out. During day, in winter, sunshine should be welcome.

It would be apparent from the above general observations that there is enough scope in our country for devising better and fresher architectural solutions and that climate is bound to play a decisive role in evolving architectural expression in our country. The influence of climate would be more apparent, because while dealing with it architecture adopts measures primarily on external surfaces to be seen by everybody. Therefore, whatever more effort we can give to the problem of climate would pave the way for a better and truer expression for the architecture of our country. Airconditioning would surely some day manufacture climate as per our requirements but that would take time and its benefit would only be taken by a handful in large cities. The vast bulk of the country would have to face the climate and nature as they are and it is better that architectural solutions within the means and for the maximum benefit of the largest number are attempted.