Design and fabrication of wooden grid shells using small-diameter timber

As the construction industry shifts toward sustainability, timber has emerged as a primary renewable material. However, current wood value chains are often inefficient; a significant portion of harvested timber—particularly small-diameter roundwood—is relegated to low-value uses like thermal energy or fiber products. Despite being underutilized, these thinnings possess a continuous fiber structure that offers higher and more consistent bending strength than sawn beams. To explore this material’s structural potential, a 6×6 m wooden grid shell was developed. This case study combines the geometric efficiency of Hyperbolic Paraboloid (Hypar) structures with the inherent strength of small-diameter logs. Realized during a one-week design-build workshop, the project utilized locally sourced logs through a digital-material workflow consisting of three main phases: 1. Debarking: Careful processing of raw logs. 2. On-site Assembly: Rapid construction of the shell framework. 3. AR Integration: Use of Augmented Reality (AR) to ensure high accuracy and robustness when working with irregular geometries. The findings demonstrate a scalable approach to valorizing low-grade timber, reducing waste, and optimizing value chains. By blending contemporary digital tools with insights from historical construction, this research offers a viable model for sustainable, low-impact timber architecture that transforms irregular roundwood into high-performance structural systems.