Towards Circular Timber Construction: Benchmarking Material Use in Nordic Timber Buildings

Timber construction is increasingly promoted as a strategy for reducing the environmental impacts of the built environment; however, timber is often treated as a homogeneous resource despite differences in the structural and functional requirements of building components. This study investigates component-level timber use intensity and the distribution of performance requirements across Nordic timber building typologies. Thirty buildings were analyzed, comprising ten attached and detached (A&D) houses, ten apartment buildings, and ten service buildings. Timber quantities were classified into ten building components, normalized by building floor area, and grouped into high- and low-performance categories according to their structural and functional requirements. A&D houses exhibited the highest average timber use intensity (0.401 m3/m2), followed by service buildings (0.257 m3/m2) and apartment buildings (0.167 m3/m2). High-performance components accounted for approximately 80%, 86%, and 75% of total timber use in A&D houses, apartment buildings, and service buildings, respectively. Although apartment buildings had the highest proportional allocation to high-performance components, A&D houses exhibited the highest absolute high-performance timber intensity (0.322 m3/m2). Component-level distributions also differed, with external walls and roofs dominating timber demand in A&D houses, floors in apartment buildings, and a more distributed pattern across external walls, roofs, and floors in service buildings. The findings demonstrate that total timber intensity and component-level performance requirements provide complementary indicators of timber demand. The proposed classification offers a basis for component-specific material optimization and more informed timber resource allocation, including further investigation of suitable lower-grade and recovered timber in less demanding applications.