Instead of a surface, the roof is conceived as a volume, and acts structurally as a beam - similar to airplane structures. A custom-made algorithm distributes strips of timber which cross in two directions to create a stiff shell, aligning to the main directions of stress in the roof. The density of timber strips is proportional to the localized stresses and proximity to support posts. The lightweight stressed skin structure makes use of low-grade and recycled timber, which would otherwise not be suited for the construction industry and be used as fuel. To prevent difficult joints or massive customization of joints, there is a high degree of repetition in the structure. Slender timber posts are organized in clusters to support the roof construction, the density of clusters being proportional to adjacent span lengths.