Since the dawn of time, man has built shelters to protect himself from his environment, whether from predators, rain, cold or heat, using readily available materials: wood, stone, plant fibers, and of course earth. Over time, techniques have been perfected and habitats have become more complex, such as the 6-story earthen buildings in Sana'a, Yemen. So, is earth construction resistant ? Well, of course.
The monoculture of concrete
Since the development of Portland cement in 1824 and the advent of reinforced concrete, the construction industry has experienced a boom in the use of concrete, gradually replacing all other materials traditionally used as load-bearing structures.
Indeed, in the European context where labor is now more expensive than the material, concrete is becoming more attractive than earth, for example, which, although almost free as a raw material, requires more human labor. What if going back to earth material was a way to have a strong social impact and to reinvest in the local economy?
In most developing countries, however, building with concrete is often more expensive than building with earth. So why are we seeing a boom in this "grey gold"? Because it reflects a certain image of wealth and "modernity" conveyed by the emblematic architecture of the North, the international style.
In agriculture, the disastrous consequences of monoculture and our current mode of food production are now known: leaching and impoverishment of the soil, spread of diseases, use of polluting pesticides that have become indispensable, loss of biodiversity, and so on. In the same way, the "monoculture" in construction - in this case the monoculture of concrete - has serious consequences: contribution to global warming through the energy-intensive production of cement, depletion of sand resources, disruption of aquatic environments (due to the extraction of marine sand), significant production of waste that is difficult to recycle, heat islands, etc. It is time to (re)introduce diversity into construction for a responsible and resilient architecture.
A surprising material
Earth is an extremely virtuous material because of its almost zero carbon footprint (if used raw and not stabilized with cement), its availability, the accessibility of construction techniques, its load-bearing capacity, its thermal capacity, its moisture management, its "reparability" and finally its "recyclability".
Because of its exemplary carbon footprint and its intrinsically local character, earth is gradually regaining credibility in Europe. It is also with great pleasure that we are witnessing a wave of renowned architects who wish to give earth back its letters of nobility (such as the "House of Grass" in Ricola designed by Herzog & de Meuron2) as well as a renewed interest in this type of construction, supported by the TERRA Award3.
If you want to know more about this amazing material, you can also read this article.