Reducing the environmental impact of construction by using local materials
It is very important to us when building community infrastructures, to reduce the environmental impact to a minimum. The energy needed for the production and transport of materials does not just increase the costs of construction considerably, but can also have a significant impact on the environment.
The “grey energy” calculation includes the full analysis of the life cycle of the product: Planning, extraction and transport of raw materials, transformation of materials and manufacture of the product, commercialisation, transport, use and implementation and finally, any possible recycling. From this point of view, local materials that are either not transformed or only slightly transformed have a distinct advantage over the others: Stone, earth, clay, straw, wood or wool are all materials that can be used in modern construction and that have very low « grey energy ».
In the remote areas of central Afghanistan, the long distances needed for transportation increase the “grey energy” rate. The manufacture of some construction materials also plays its part in inflating the energy costs and has a negative impact on the environment. For this reason stone was chosen rather than clay bricks for the majority of Nai Qala constructions. Although there is an almost limitless availability of clay and it is totally recyclable, the firing of bricks involves high energy consumption that can last up to several days at temperatures of more than 1000 degrees. The kilns sometimes function with the use of fossil fuels or often with wood sourced from already arid regions, which contributes to deforestation.
When choosing a construction company and signing contracts the construction materials are chosen very carefully so as to ensure safety and comfort for those who use the building at the same time as keeping the environmental impact to a minimum. For example, Sokthagi school is built from stones extracted from the nearby mountains and are cut to size on the spot. The grit and sand used for the mortar come from a river close by. Only the wood for the framework, windows and doors is transported from other regions. The sourcing of materials brings about a more positive ecological balance to the construction.