Evaluating the sustainability of the bahareque construction technique using environmental and social Life Cycle Assessments (e-LCA and s-LCA): a case study on a minimum house in Ecuador

The evolution and management of the Built Environment are critical components of today's societal challenges. The construction sector, therefore, plays a vital role in meeting the global demand for (affordable) housing materials and techniques that minimize both environmental and social impacts. This study explores the potential of traditional composite wood-clay shear wall systems, known in the Americas as bahareque, as a viable alternative to conventional block masonry construction. For this, a comparative evaluation between the two types of walls was conducted using environmental Life Cycle Assessments (e-LCA). Social Life Cycle Assessments (s-LCA) and an ethnographic method were applied to explore bahareque constructions sustainability beyond environmental aspects. This study builds upon a minimum house model, located in the Andean Region of Ecuador (i.e., 83 m², designed for 3 occupants with 7 functional areas) over its entire lifecycle. The findings indicate that the carbon footprint of the minimum house (measured as the Global Warming Potential, GWP100) can be reduced by 30-40% when using bahareque. For the s-LCA residents show uniformly positive outcomes, while construction workers had more heterogeneous results (e.g., high satisfaction and a high percentage of minimum wage access offset by limited association rights and formal contracts). The study also reports how cultural mechanisms - community structure, family, and cooperative labour - help to preserve bahareque construction technical knowledge. Subsequent investigations are required to address residual environmental and social impacts. Overall, these insights aim to foster better-informed decision-making in environmental, social and cultural terms for the Built Environment.