Reusable timber modular buildings, material circularity and automation: The role of inter-locking connections

As sustainability becomes a central concern in construction, the industry witnesses a significant surge in the adoption of material circularity principles, reflecting a new approach to resource management. Although mass timber construction holds significant potential for end-of-life (EoL) material circularity due to its natural materials and prefabrication, conventional connection systems hinder material reuse. Integrating interlocking techniques into modular construction could enhance circularity and enable future autonomous construction. This paper summarises design-for-reuse (DfR) strategies focusing on connection design for rapid assembly and disassembly of Cross-Laminated Timber (CLT) modules. These strategies can promote innovative connections with enhanced material circularity, which were illustrated through a recently proposed conceptual interlocking connections (MOD-IT). Additionally, a comparative cradle-to-cradle Life Cycle Assessment (LCA) evaluates the environmental impact and circularity potential of timber modular buildings using this connection system. The study underscores the pivotal role of strategic connection design in achieving a closed-loop system in timber construction. This advancement fosters sustainability by improving efficiency, adaptability, reusability, and autonomy in the construction process. • A comprehensive review of connection design for reuse (DfR) strategies is presented. • The role of interlocking connections in enhancing construction efficiency and circular economy is explored. • A novel interlocking connection designed specifically for Cross-Laminated Timber (CLT) modular construction is introduced. • A comparative Life Cycle Assessment (LCA) is conducted for CLT panelised and volumetric buildings, examining both conventional and interlocking connections. • The potential of timber modular construction with interlocking connections in facilitating autonomous construction is discussed.