Adapting Medieval Heavy Timber Joinery for Modern Circular Mass Timber Construction

Abstract

The global construction industry occupies a critical threshold in the climate crisis, accounting for approximately 37% to 40% of annual greenhouse gas emissions. While mass timber products sequester biogenic carbon during growth, contemporary fastening methods rely heavily on permanent polyurethane adhesives and high-torque metallic connectors. These standard practices force a linear ‘take-make-dispose’ model upon building decommissioning. This paper presents a comparative review of medieval European heavy timber framing (approx. 1000–1500 AD) to evaluate how historic joinery principles can be applied to modern contexts. Specifically, we analyse how wood-on-wood configurations can be re-engineered via 5-axis Computer Numerical Control (CNC) milling to enable true Design for Disassembly (DfD). The research addresses technical limitations inherent to adhesive-free systems, including significant bending stiffness losses and acute sensitivity to moisture variations. To mitigate these risks, we evaluate modern material enhancements, such as the integration of compressed wood (CW). Ultimately, this analysis provides a conceptual and structural framework to bridge historic carpentry craftsmanship with automated construction. The proposed system ensures twenty-first-century timber components remain suspended in a circular state of structural value rather than descending into material downcycling.