Thin earth: Bio-stabilised pressed thin earth elements for building applications

Earth is gaining renewed attention as a building material due to growing environmental concerns in construction, offering a healthy, low-carbon, and low-energy alternative to conventional methods. It is typically used for thick masonry or monolithic walls, often stabilised with cement, or as finishing layers like plasters and mortars. To the authors’ knowledge, thin earth elements are virtually absent. This study introduces bio-stabilised pressed thin earth elements for non-structural applications, using biopolymers (locust bean gum, sodium alginate) and natural fibres from banana pseudo stem. Agro-waste fillers, including rice husk and wood shavings, are also explored. At the intersection of fabrication, performance (mechanical, thermal, microstructural), and environmental impact (GWP), the results demonstrate the feasibility of producing cementless, unfired thin earth elements with tailored properties. Biopolymers enable fabrication and enhance toughness, outperforming lime, while natural fibres significantly improve ductility. Agro-waste fillers reduce soil use by up to 15 % and enhance thermal performance. A performance-based environmental assessment shows a competitive GWP compared to commercial alternatives. Long term, these results broaden earth’s role in construction, from structure to finish, offering a sustainable alternative to energy-intensive, petroleum- and cement-based thin components, and supporting a new generation of responsible building. ● Bio-stabilisation enables thin, unfired, cement-free construction elements. ● Mechanical behaviour varies greatly depending on the bio-stabilisation strategy chosen (biopolymers, natural fibres). ● The mechanical performance of bio-stabilised elements exceeds that of lime-stabilised elements. ● Biopolymers and fibres can have a significant environmental impact.