Development and Implementation of a Foundation System Made of Demolition Concrete in Clay Construction: A Contribution to Sustainable Building Practices Part 2 Dissertation 2026 Boris Dobrinic University of Liechtenstein | Liechtenstein This study examines the development and practical implementation of a foundation system made from reused demolition concrete for clay construction. It investigates whether load-bearing, resource-efficient, and low-cement foundation solutions can meet the structural requirements of clay buildings while supporting circular material use.Although clay is increasingly valued as a regional, low-carbon, and recyclable building material, its sensitivity to moisture requires reliable foundation strategies. Conventional concrete foundations provide effective moisture protection but are associated with high CO2 emissions and limited recyclability.The Lehmraum Liechtenstein project served as a full-scale case study for testing an alternative foundation concept. The system combines reused demolition concrete, capillary-breaking layers, targeted drainage, and clay-based waterproofing. Particular attention was given to layer construction, mechanical compaction, and continuous monitoring during implementation. The project was realized through close collaboration between craftsmen, students, and regional partners, allowing practical feedback to inform the design process.The results demonstrate that reused demolition concrete can provide a stable and durable foundation while significantly reducing the demand for primary raw materials and lowering the building's carbon footprint. At the same time, the study highlights that successful implementation depends on careful planning, proper compaction, appropriate layer design, and effective moisture management.The research argues that sustainable construction should prioritize the responsible use of existing resources rather than relying solely on new materials. It concludes with practical recommendations for the planning and execution of circular foundation systems and highlights the value of collaborative, practice-based research for advancing low-impact construction methods. Tutor(s) Cornelia Faisst Martin Mackowitz