Earthen Architecture and Green Building Techniques
A solution provided by Auroville, India
Construction is responsible for the huge consumption of energy, electricity, water and materials. On the other hand the building sector has a great potential to deliver significant cuts in emissions at little or no cost. Buildings account for 18% of global emissions, or the equivalent of 9 billion tonnes of CO2 annually. According to the United Nations Environment Program, the emissions could double by 2050 during this time of rapid growth. With so many refugees and other people worldwide looking for shelter, solutions are needed for how to build with local, natural and affordable materials.
The Auroville Earth Institute (AVEI), specializes in the research and development of earthen technologies; which are cost effective, low carbon, low embodied energy solutions for sustainable development. This includes Compressed Stabilised Earth Blocks (CSEB) walls, Hollow Interlocking (HI CSEB) walls for disaster resistance, CSEB arches, vaults and domes, Stabilised Rammed Earth Foundations (SREF), Stabilised Rammed Earth Walls (SREW), Earth composite technologies for columns and beams, Stabilised earth waterproofing, plasters and mortars, etc.
The most promoted AVEI technology today is Compressed Stabilised Earth Blocks.
The Kaza Eco-Community Centre aims to promote renewed use of traditional Tibetan building techniques and materials in the valley, while introducing a number of modestly innovative features to improve the seismic resistance, thermal comfort and energy efficiency of buildings in this context. The building, which consists of a stone masonry foundation, CSEB elements, and raw rammed earth walls, has been designed especially for the harsh winter climate of Spiti. Trombe walls have been incorporated for passive heating of the building during the winter. As the region is prone to seismic activity, earthquake-resistant features have been incorporated. Buttress walls have been added for lateral stability. Since vertical reinforcement can be problematic in rammed earth, horizontal reinforcement has been extensively used. This includes ring beams with AVEI's CSEB U-block system and bamboo reinforcement embedded into the rammed earth walls and buttresses at critical corners of the building.
An example of earthen architecture applied in a community is the Vikas community in Auroville. It was designed and created based on a particular spirit, life style and appropriate architectural design. The design implemented environmentally sound materials, appropriate building technologies (earth and concrete), renewable energies (solar and wind) and ecological water management (watershed harvesting and biological wastewater treatment).
The community was built in several stages, from 1992 to 1998. The community kitchen was built first to emphasize the communal aim. Then a block of 4 apartments was built and later on a second block with 5 apartments. The third block with 13 apartments was built on 4 floors without RCC columns: a basement floor with three floors above it. This design allowed the building to be self-sufficient for its soil needs. The soil was dug from the basement floor (1.20m below the original ground level) to produce adequate compressed stabilised earth blocks to complete the structure of 819m2 area on 4 floors. Vikas community was a finalist for the 2000 World Habitat Award.