Architects around the globe have finally come to terms with the impending climate and biodiversity degradation issue as the most serious of all time. This isn't an abstract hazard; it is very much a reality. Cities need to move towards becoming self-sustaining, and it all starts with going back to the primitive material- Earth. The forthcoming architects have to accept the responsibility to propagate natural materials and techniques when incorporated breaking the viscous construction cycle.
Earth Architecture is heavy and responds to changes slowly over time. It isn't renewable, but it does reduce the CO2 footprint. Earth can be manipulated into various desired forms- the Playdoh of every architect’s dream. The aesthetic value is striking, but there is a deeper story. It is time to look for alternative material options. Here are some ways in which you can narrate your earth architecture story to the world.
The rammed earth construction has layers of earth mixed with water, then rammed between shutters. The resultant is an outstanding physical construction paired with a unique aesthetic value. Earth has different shades, colours and textures each time it is poured. This earth monolith acts as an air barrier which regulates the indoor climate, humidity, and temperature and reduces carbon emissions. It is a low technology technique with high potential. Although it does have some structural drawbacks. The thickness is not always preferred, and it does require significant pre-fabrications.
Areas with cohesive soil which contains carbonates can be cut in the shape of blocks and laid like bricks for the building envelope. Such soil is typically found in tropical areas with laterite soils. These blocks harden into a durable material with proper exposure to air and sun.
This technique is like pouring concrete in the formwork only the concrete is liquidated soil. This approach does have a setback by shrinkage. Once the wall has dried, the walls have cracks, thus low structural integrity. To tackle this problem, significant research is in progress where the walls after drying, do not shrink.
SuperAdobe is a technique where sandbags are loaded with dampened earth and arranged in a coiling layer. Barbed wires are placed between each bag as mortar and reinforcement. This building system is used for arches, domes and vaults. Superadobe can be a permanent structure if plastered over to protect from weathering. The plaster also creates an organic aesthetics to structure.
Adobe bricks are mud bricks made from high clay earth and straw. Each brick is manually produced with the earth mix cast in open moulds and left to dry under the sun. When constructing a wall, these bricks are laid with earth mortar. Often a clay coating is applied on the surfaces to smoothen the walls. The adobe bricks are fire-resistant, durable and non-toxic material, providing excellent thermal comfort indoors. The adobe bricks can have holes for reinforcement to increase structural stability.
Cob is a blend of clay-rich soil, sand, fibre and water. The ingredients are mixed to form a dough-like consistency and then stacked on top of each other to create a structure. Cobs result in thick walls with round cornered buildings. It turns the architect into a sculptor with its clay flexibility. There is no formwork used to build these walls with this technique. The advantages of this technique include low-cost material and simple construction. On the contrary, it is a labour-intensive technique with a slow construction process.
Compressed Stabilised Earth Blocks (CSEB) are produced from local soil mixed with 5% cement, sand and water. They are further pressed and cured for 28 days for their compressive strength. It is a great alternative to burnt bricks or concrete blocks. The quality of blocks is influenced by soil quality, curing, manufacturing and compressive forces. The bricks can be made at the site itself, thus ensuring quality and cost-saving. These blocks aren't suitable for high rise buildings and require trained labour.
This technique can also be referred to as Daubed Earth. It is made of vertical wooden pieces (wattle) interlaced with the horizontal branches. Wattle can be formed with thin branches like vines, reed or bamboo. This arrangement is, then daubed with earth, and left to dry. The wattle daub technique can be achieved more quickly and efficiently than another approach. The lattice holds together the earth like glue without comprising the structure.
As the name suggests, this approach is like how potters shape pots with mud, the shaped earth is directly forming the structure without any formwork. The soil, its water consistency and preparation- play a crucial role in this method. It needs minimal tools and labour. The designer should keep in mind the shrinkage after the structure dries. It provides fluidity and flexibility in design.
Straw and clay is a mishmash of straws chopped into tiny pieces and mixed with gooey clay. This mix is plastered inside a timber frame with rammed earth. It is a lightweight construction and thus isn't load-bearing. The technique results in a good thermal and acoustic insulated building envelope.
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Clay has unparalleled potential in sustainable construction as it tackles carbon emissions and has low embodied energy. A great alternative to cement and lime materials. Earth is a circular raw material that is almost inexhaustible when kept in its original form without any additions and burning; can be recycled back to its initial composition. Embrace earth architecture as the overlap of sustainability and natural poetry.
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