Climate change– an ominous and adverse development exhibiting shift in weather and climate worldwide, which is associated with increase in global temperature. The gruesome after effects of climate change that the world is facing currently, are natural disasters like floods, forest fires, disease outbreaks, etc. and human crisis like famine, poverty, mass migration and war.
Concentration of carbon-di-oxide in the atmosphere is one of the biggest causes of climate change. An average building consumes 40% of energy in its making and emit half of the carbon-di-oxide due to burning of fossil fuels such as oil, coal, etc and cement production. This emission traps the solar heat on surface of the earth, making an average building and by association the architecture fraternity equally responsible.
In the current scenario, the fundamental prominence should be given to the issue of climate change with respect to the building design. As architects we are abided by an obligation to our planet as to see that sustainability is achieved in every aspect of planning and designing. It is one of the unfortunate choices that we as a community face- whether to build an environment which is sustainable to control or omit the carbon-di-oxide emissions totally or to continue with the business and live with the after effects.
In order to accomplish sustainability, accurate knowledge and study of building materials is of utmost importance.
Vernacular materials- traditionally used and locally available materials fall under this category. In the past years, these materials were under the scrutiny as modern replacements were being developed. But today, with the awareness being created about climate change and a more sustainable approach, they have gained renewed attention. They are being innovatively used as they are financially feasible, environment friendly and technically reliable.
Listed below are some of the Vernacular building materials which can be used to tackle climate change.
Earth is the oldest building material used. Primary earthen building materials include-
- Adobe bricks– these are made from clay, sand and straw. The mix is cast in open mould onto the ground and sun dried (not kiln-fired). They arefireproof,durable yet biodegradable, non-toxic building material which provide sufficient thermal mass to buildings to ensure excellent thermal performance. These can be made on site, reducing the transportation cost.
Prominent structures made from adobe bricks-
Arg-e-Bam- largest adobe structure in the world, located in Bam, in south-eastern parts of Iran.
- Rammed earth– is a compact mixture of subsoil compressed with fibres for stabilization.
They have low embodied energy, high thermal mass and are hygroscopic. It is one of the favourites of architects around the world and is been extensively used in modern buildings.
A few examples include- Auroville Earth institute.
- Cob– it is made from clay, sand and straw that are stacked and shaped while wet. It is made from locally available materials, fireproof, resistant to seismic activities, low cost.
Bamboo is considered to be an ideal building material, as it has great tensile strength, it is light in weight and is renewable in nature. It is used for framing buildings and shelters. Especially, post-disaster rebuilding, refugee shelters and low-income areas. It is an efficient replacement to the expensive and heavy imported materials and it provides an alternative to concrete and rebar construction. Bamboo is also used for aesthetical treatment due its voguish appearance.
Wood naturally sequesters carbon, which reduces the carbon emission. It produces much lower amounts of greenhouse gases in comparison to other building material. Wood although being one of the best materials to tackle climate change, is obtained from cutting of trees. Hence, to solve this issue, reclaimed wood can be used as an alternative. One of the best materials to reduce the contribution to climate change is reclaimed wood. It avoids cutting of trees as it does not need production of new wood.
With new technological progress made every day in the construction industry, many contemporary materials are been developed. These materials serve the purpose of being user-friendly, in some cases, cost effective and as an ideal solution to the issues faced due to climate change. Some of them are listed below-
Mycelium are the rootlike fibres of fungi which grow beneath the surface of the ground in the form of mushrooms. When they are dried, they can form a material with extreme strength. Mycelium is water resistant, fire resistant and mould resistant. It is sturdy and bullet proof. It can withstand extreme temperature. It is 100% organic in nature and compostable. It can be grown and moulded into building blocks of varied shapes and size.
The components of this material include, sawdust and a small number of mushrooms. The fungus consumes the sawdust nutrients, its mycelium grows into a solid block of cells which can be confined into moulds.
If two living fungal bricks are kept, they will fuse into an unbreakable bond within few hours, the blocks need to be dried or cured, which kills mycelium, resulting in rigid building blocks, which can be painted.
Ferrock is a greener alternative to cement. It comprises of recycled materials such as waste steel dust and silica from the ground up glass. It absorbs more CO2 than it emits. It is five times stronger than Cement and traps greenhouse gases reducing carbon footprint. It is lightweight and has low maintenance cost.
AshCrete is a concrete alternative that uses fly ash instead of traditional cement. By using fly ash, a by-product of burning coal, 97 percent of traditional components in concrete can be replaced with recycled material. AshCrete can greatly improve traditional concretes strength and durability while decreasing its permeability.
Quoting Archbishop Desmund Tutu, “The destruction of Earth’s environment is the Human Rights challenge of our time”.
As architects, our duty is to make a correct call on the building materials, although prioritizing the environment. Let’s grasp the contemporary and re-embrace the traditional.