“I like to welcome Nature and I take Architecture as a dialogue with nature, our nature and the nature of the world around” ~ Didi contractor
Building materials are like the ingredients that make up a dish, except it can’t make for a Sambhar or Gravy, but is the basic unit of a building. Now unlike cooking the outcome doesn’t solely just depend on the ingredients and the skill set of the cook. It depends on various aspects of the built environment that influence and mould the building.
Understanding building materials and their properties is crucial to creating a sound building. Romans realised the full potential of concrete and used it exhaustively in order to create remarkable structures that stood the test of time and deemed fit for the function it was assigned initially. Our predecessors used materials around them, understood their properties, used them to their advantage and valued them for what they were for it proved to be versatile and earth friendly.
Sustainable Architecture focuses on design processes that consciously include strategies that minimises negative impact on the environment. It is a term so vast that encompasses several processes pre, post and during the construction process. For example, it starts from procuring materials that has lower embodied energy and utilising it as is devoid of finishing process that could be harmful and toxic to the environment. Sustainability should be a core aspect of every field. Any process/material/technique that poses a threat to the atmosphere & environment shouldn’t be encouraged. It has become ever so important nowadays to be mindful of decisions that could impact a larger setting. Large scale project or otherwise, to actively employ sustainability cautiously is vital in today’s times.
Let us now look at a series of eco-friendly building materials that were used ages ago that proved to be favourable, locally available and above all entirely sustainable.
COB
Cob is a striking mix of subsoil, water & fibrous material that has been in use since prehistoric times and has been proved functionally fit for hot & arid climatic conditions. Did you know that the oldest cob structure still stands and it is estimated to be 10,000 years old? Cob typically keeps the structure cool during the day and provides warmth during the night, by absorbing energy during the day and storing them to emit it out in the night. A cob structure pairs with earthen building materials like thatch for roof, bamboo for structural support etc, which interestingly makes the end product a 100% compostable.
Rammed Earth
Rammed earth is a material that is obtained by compacting certain soils. This is appropriately a technique rather than a material and has been in use since the Neolithic period! This technique surprisingly was used for great structures and for humble homes, and would any of us believe that the Great Wall of China was built on this technique! Just like the trusted cob, Rammed earth holds very low embodied energy, produces less to no waste products during its make and is compostable! It isn’t a great performer thermally like cob although it permits insulation to sit over it.
Lime
The many monuments that we have visited during our childhood have all employed Lime in the most obvious ways. Lime was used as mortar (binding material between bricks) & as plaster (finishing material over the brick course) predominantly in India and in other countries like Africa, South America, China etc. Lime that we use in construction is called quicklime, that is nothing but calcium carbonate without carbon dioxide. Lime has its array of benefits that are hard to ignore.
Firstly, it turns your building into a living being! Not kidding but Lime makes a building breathe, which means moisture isn’t trapped and is free to evaporate. Secondly it keeps the interiors cool, that is, it has the ability to bring down the internal temperature to a considerable 3 to 4 degrees lesser! Lime along with other natural building materials, sustainable building techniques, employing passive cooling strategies could do real wonders.
Adobe
Adobe is another versatile building component that is usually seen in the form of a brick. Adobe bricks are made of mud and straw. These bricks are only sun dried. They work well with clay mortar and the surface is smoothed out before the setup dries. People often find an additional application of mud plaster useful in terms of a smooth and even finish. Adobe is completely earthy, non-toxic, fireproof and it could be rummaged down back to the earth if wanted. Adobe allows shrinkage to happen during laying itself that would later prevent the same from happening. Adobe is flexible as a material and comfortably accommodates grooves for service or reinforcements!
Stone
Stone structures have long been in use for its sturdiness, strength and appeal. Stone is used for wall claddings, flooring and even sizable bricks that make up the wall itself. Although now it’s use is reduced to foundation level, it is extensively used in terms of flooring (Granite, marble) that undergo extensive refining process for a greater finish which is again harmful to the atmosphere and soil. Stone construction that employs less finishing processes could be termed sustainable due its longevity & strength. Temple construction in India and around the world saw extensive use of stone for construction and sculpting.
Bamboo
Bamboo is a well-known building material that is available in abundance in tropical countries. It’s unmatchable strength and flexibility render economically built structures that can almost be entirely built out of bamboo and is definitely long lasting. Did you know that Bamboo’s tensile strength is higher than that of steel itself!! Bamboo is lightweight, easy to work with & works well in seismic zones too. Bamboo has high potential in terms of creativity, flexibility and sturdiness. Bamboo will require rigorous chemical treatment before it is put to use. Bamboo is highly desirable since it grows ridiculously in a given set of time, i.e., it grows 4 feet in 24 hours. It has the potential to grow 15 times faster than traditional lumber (wood used in construction).
Strawbale
This type of construction uses bundles of straw compressed into rough blocks that come together as structural elements & as insulation too. Straw bales are preferred for their low embodied energy, excellent insulation property, 100% compostability & their affordability factor. Strawbale construction along with lime finish can render a healthy atmosphere to live in. Certain research findings also claim that fire resistance can also be promised if the construction has been carried out judiciously. Construction is comparatively simple and easy on the pocket if the skill set of the building crew is in place.
There is so much knowledge that our ancestors possessed in terms of materials. Techniques & procedures which makes so much sense even today. Recognising a material’s potential to use it but not entirely exhaust it is mandatory in current times. History brings with it valuable information that is ought to be understood, put to use and most importantly treasured.