Low-Cost Sustainable CEB Dwellings

The world is currently undergoing an ecological crisis of unprecedented scale and urgency, in which building and construction are responsible for 40% of all carbon emissions in the world [1]. Existing advances in sustainable dwellings usually involve high-tech equipment used by highly skilled workers on-site, which may not be suitable for less developed countries, for example Morocco. This project aims to provide a customizable design and simple construction process that enables local workers in Morocco to build sustainable, low-cost housing with locally available earth material.

Earth buildings provide good comfort and have minimal embodied energy as well as a light environmental impact. Morocco has abundant earth resources and vernacular earth architecture. However, using earth for constructing dwellings has been gradually abandoned since the introduction of concrete. Despite recent attempts to bring back earth construction with rammed earth and compressed earth blocks (CEB), the material is usally stabilized with cement. Often, the structural components made of earth are also only used for the walls and another material and construction technique for the roof is needed, which can make up 50% of the cost of the entire building construction [2].

In research conducted by the project team over the past two years, a parametric design template is proposed that enables a mortarless CEB dwelling where the wall and roof systems are built with the same technique and material, thus reducing demands on infrastructure, materials, and building skills [3]. This work will now be adapted to the Moroccan context by determining an appropriate architectural layout that can be built with only a few interlocking CEB block types to simplify the construction process. To enable an existing conventional CEB press to fabricate customized CEBs, this research investigates how to make the minimum modifications to a conventional CEB press. A small-scale, raw earth structure was constructed successfully in the summer of 2022 at ETH using a limited number of 3D printed molds to make interlocking CEB block types using a manual CEB press. A full-scale prototype will be developed and built together with our local partner in Morocco in the intended culture, context and climate. This is vital to demonstrate the potential of our approach to a wider audience thus, leading to greater potential impact in low resource settings.

This research will demonstrate a balanced combination of new technologies and conventional processes to enable the design and fabrication of bespoke and efficient architecture in the context of developing countries. It makes the design and construction of a broader range of innovative and sustainable structures more accessible, affordable and adaptable to all.

Project Partners: Arup (United Kingdom), Gianni Botsford Architects (United Kingdom), Cooperative Belarej and Argilex Sarl (Morocco)

References:
[1] World Green Building Council. 2019. “Bringing Embodied Carbon Upfront.” Accessed September 13, 2021. https://www.worldgbc.org/embodied-carbon.
[2] UN-HABITAT. 2019. “Interlocking Stabilised Soil Blocks: Appropriate Earth Technologies in Uganda.” Adrián Mauricio Pérez-Peña
[3] Zhang, Y., Tatarintseva, L., Clewlow, T., Clark, E., Botsford, G., Shea, K., “Mortarless Compressed Earth Block Dwellings: A Low‐Cost Sustainable Design and Fabrication Process”, ACADIA 2021 (In press).