From forest to building: Enhancing the use of lower grade wood for climate-responsive construction

• Shifting timber to construction boosts its climate mitigation potential. • Low-grade timber use stores more carbon by extending product lifespan. • Strategies must reflect local growth rates, rotation, and practices. • Innovative regional uses of low-grade wood are key for climate benefits. • Research should expand uses of low-grade wood and optimise supply chains. The construction sector, a major contributor to global greenhouse gas emissions, offers considerable potential for climate change mitigation through the substitution of traditional building materials with timber. While engineered wood products like cross-laminated timber and glulam have gained attention for structural applications, the use of lower-grade wood and industrial residues for durable, non-structural construction elements remain underexplored. This study evaluates the opportunities and challenges of incorporating low-grade wood into construction, specifically assessing potential climate benefits, mapping material flows along the wood value chain, and modelling carbon storage dynamics in products and by-products over a 100-year horizon, all based on secondary information sources. Using case studies from Mexico, Spain, and Chile, we analyse timber use scenarios that integrate lower-grade wood into construction materials. Results show that redirecting lower-grade wood into construction can increase carbon storage in products by 2% to 35%, depending on species growth rates, rotation lengths, sawmill efficiency, and timber quality. Yet, quality constraints and logistical barriers limit large-scale adoption. Unlocking this potential will require improved forest management, advanced processing technologies, and supportive regulatory frameworks. The findings demonstrate that both structural and non-structural applications can extend the lifecycle of wood and amplify its climate benefit, while regional differences in species growth, rotation lengths, and timber quality highlight the need for context-specific strategies to realise this potential.