“To create nice and more importantly, meaningful, appropriate atmospheres, we need to focus our attention not on the quantities but on the qualities.”-Day, Christopher (1990:46)
Architecture is one of the oldest professions in the world. From the primitive cave paintings of Bhimbetka to the Harappan civilization to the current age, one thing that is common is the need for habitable spaces that can sustain the people of that civilization and their socio-economic activities. If studied closely one would notice that these shelters, which were made, were simply the best possible answer to the question of intolerance of the harsh environment, to make it liveable.
Available technology and materials along with the study of the climate- governed the design. However, with the advancement in technology, we have started building a more efficient and more luxurious habitable area but the basis of design i.e. to protect ourselves from the environment remains the same. Reducing the scope, what follows is a list of 10 things that an architect must remember while designing in the harsh Tropical Monsoon Climate. The list reflects and takes into accounts the original factors which were considered while designing by our ancestors and the locals of the area as nothing can explain a climate better than the vernacular architecture of that area.
1. Site location
Humans out of all the other animals have the least adaptability. Research has shown that constant change in the temperature of the environment causes psychological effects on our brain such as irritability and inefficiency. Hence to maintain a constant comfort zone site location and study is of uttermost importance. Sites near lake or sea have an advantage of air current and humidity whereas sites on/near mountains have cooler temperatures. Every site has its advantages and challenges which need to be molded, manipulated and harvested to obtain the best user-friendly design.
The orientation of the building should be such that it harvests the forces of nature for the benefit of the user. The orientation should reduce direct sunlight inside the structure however it should allow glaze free indirect light. The structure should be along the prevailing wind direction to maximize ventilation. It must also be noted that- The highest intensity of radiation falls on the roof and west walls, and it is slightly less on the east walls. This is because the morning temperatures are lower. The relative areas of the building surfaces may be adjusted to minimize heat gain due to solar radiation.
3. Form and planning
As the movement of air is only available to relieve the climatic stress, therefore it is vital to catch indoor comfort by opening the building to the breeze. Elongated plan shapes with a single row of rooms to allow cross-ventilation, accessible from open verandahs and galleries are generally provided.
4. Openings and shading devices
Since we are designing for Tropical Monsoon air movement should be given high priority as it brings down high temperatures and reduces the humidity in the shelter. However, one should make sure that the size of the opening is appropriate. The design of large openings may get unnecessary heat through radiation hence shading devices are essential. Shaded courtyards around the house were designed for the same.
Wall insulation is not necessary if they are shaded. However if the walls are exposed to solar radiation (such as gable walls), good insulation will prevent the elevation of inner surface temperatures above the air temperatures. Reflective qualities on the outer surface of such unshaded walls will also be helpful.
Roofs should have a reflective upper surface, a double roof construction with roof space ventilated, a ceiling with its upper surface highly reflective and having good resistive insulation. Both the ceiling and the roof should be of low thermal capacity.
As the outside temperature remains mostly constant the building cannot cool itself sufficiently at night to allow the storage of heat during the day. The principles of Thermal storage cannot be relied on in this climate. Hence it is advisable to use low thermal capacity materials, using lightweight construction.
8. External Spaces
The same principles apply to the design of external spaces as to the design of buildings. Shading and free passages for air movement are the two basic requirements. Trees and plantings can be relied on for shading, as plants carry foliage all year round.
9. Principles for Comfort in the warm Humid Climate
The condition under which man adjusts himself to the environment, with the minimum expenditure of energy, is defined as the ‘comfort zone’. It is essential to understand the comfort zone of the people and area you are designing for as it is relative to the environment.
10. Climate Modification Strategies
The basic climate modification strategies involve the use of airflow, solar gain, evaporative cooling, thermal mass, shading, etc. The design basis for selecting the appropriate climate modification strategy is to define the physical characteristics of the particular climate and the design objectives.