“There is no Planet B” is a slogan one sees quite frequently at Climate Change protests and rallies because the current generation is aware of the consequences of global warming and extremely concerned about the future of our planet. The most common answer to preserving the integrity of our planet is sustainability- a word one might see/ hear/ use quite regularly. According to the UN World Commission on Environment and Development, to be sustainable is to “meet the needs of the present without compromising the ability of future generations, to meet their own needs, especially with regards to use and waste of natural resources.”
The last few decades have seen an increase in the number of “Green buildings” designed responsibly by various architects. The One Angel Square in Manchester, ParkRoyal on Pickering in Singapore, and even the Jawaharlal Nehru Bhavan in New Delhi are a few examples of Sustainable architecture in today’s world. Presently, most architects use sustainability as a concept for their designs. This practice, however, dates back to the ancient times, when our ancestors made sure that the resources that were available in great abundance were used efficiently without any wastage. They used materials indigenous to their location to keep their habitats cool or warm depending on their climatic zone, and even constructed elaborate water supply and sewerage systems without the use of PVC pipes.
Take the Ajanta caves, for example, a series of 29 rock-cut Buddhist Chaityas and Viharas in Maharashtra. The vaulted ceilings of the Chaityas were penetrated with sun windows to illuminate the entire prayer hall. While most cases have a very high ceiling, the caves at Ajanta have a low one- done experimentally to use the tunnel effect horizontally. The low ceilings allowed the hot air to flow into the cells surrounding the prayer hall on either end, which were filled with cool water. This water-cooled the hot air which leads to cooling down of the entire cave. The stone that the caves are carved into also adds to the cooling of the space.
Another material that is great for reducing the temperature of interior spaces is rammed earth. Rammed earth has excellent thermal mass, and it can hold heat for about 12 hours after which it is radiated out. It has hence been extensively used in Middle Eastern and Southeast Asian ancient architecture, where homes were constructed using this technique to drastically reduce the temperature of the enclosed space. Ait Ben Haddou in Morocco and Granada Alhambra in Spain are two ancient villages that have been constructed completely with rammed earth. Even today, this technique remains a favorite of architects to constructgreen and sustainable buildings.
Similarly, Cob is another such natural building material that has been used since prehistoric times. It is an amalgamation of subsoil, water, and fibrous material like a straw that acts as reinforcement. Cob walls have an excellent thermal mass, just like rammed earth. Thatched roofs and Cob Walls are the perfect duos for a warm and cozy house. It is also known to withstand earthquakes.
Persian wind towers, traditionally known as Badgirs, were another type of architectural device widely used in ancient times to keep interiors of a building cool. The openings in the wind towers catch air above the ground and direct it to the lower living space, which thereby receives cooled air (as cool air sinks). A pressure gradient is hence created which directs the hot air upwards in the tower, out through the openings at its top. These towers were also used in water reservoirs in arid regions, where water could be stored at near frigid temperatures during summer months due to evaporative cooling. These wind towers are also found in Iran and Bahrain. These devices are commonly used today in the Middle East, and certain houses in Rajasthan have also been influenced by this design.
A sustainable method of heating was used in Ancient Rome baths and public buildings, using a Hypocaust. A hypocaust is essentially a centralized heating system that produces hot air under the flooring of the room, which could also be transmitted to the walls using a series of pipes. The hypocaust was raised above the ground using pilae stacks which were pillars that supported a layer of tiles. A layer of concrete was laid on the tiles, finished with the tiles of the flooring of the room above. It consisted of a furnace from which hot air circulated through the clay tiles into the rooms above, thus warming up space.
Igloos too have been used by Eskimos to keep warm for many centuries. They are derived from the primitive Quinzhee, which was temporary shelters made by carving out a hole from settled snow. Igloos are dome-shaped dwellings constructed by circularly placing blocks of snow. The blocks of packed ice serve as insulation, creating a warm environment of about 32 degrees Celsius. The tunnel that leads into the dome helps preserve heat inside, while a vent near the top helps in the escape of warm air, to prevent the melting of the ice blocks. Unfortunately, Global Warming has reduced the availability of snow appropriate for Igloo construction. Several winter destinations today have constructed “Ice Hotels” derived from the design of traditional Igloos.
The recent years have seen the development of different forms of bamboo as a sustainable and versatile building material. In some cases, it has become a premium building material. However, in ancient India and China, bamboo was mainly used by the lower class to build their houses. A number of cable bridges were also constructed centuries ago, that remain equally strong even today. Bamboo has excellent tensile strength and rigidity and almost has the same slenderness ratio as steel. It is also waterproof and renewable, making it the perfect sustainable building material. The Green School in Bali is the best example of bamboo used to its utmost potential in today’s times.
The ancient stepwells of Rajasthan and Gujarat are also a great example of sustainable architecture. These wells consisted of four walls with stairs that led deep into the earth, from where water was drawn. This water was primarily fresh groundwater. Stepwells also served as a cool community retreat in the summers. In fact, because of the lower water level during the hot seasons, the villagers had to climb additional steps which were quite saturating, which lead to the minimal use of water, thereby saving water to prevent the tiresome errand frequently.
The ethereal Angkor Wat temple complex in Cambodia was also constructed in a sustainable style. The moat around the complex and the various water bodies helped keep it cool. The temple structures were designed such that they sat on a base of sand, which provided a constant and easily accessible supply of groundwater that was available only five meters below the earth. The indigenous materials that constitute the entire structure of the complex also add to the sustainability of the complex. Excess tourism has reduced the water table of this complex, threatening its stability.
The Jerusalem water-supply system was the brainchild of the Hasmonean Dynasty that ruled Judea almost 2000 years ago. Since then, one of the aqueducts made of terracotta has remained one of the city’s primary sources of water. Water from sinks in homes was conserved and used to flush waste and water gardens, much like we do today.
It is astounding that though our ancestors had plentiful resources, they put in a lot of effort to conserve these resources for future generations. The Industrial Revolution and capitalism have led to the overexploitation of natural resources- though we cannot dwell on the past and change this phenomenon, it’s time for us to go back to our roots and implement the practices of the ancient era.