Carbon mitigation and energy efficiency of hybrid cross-laminated timber buildings: A case study on a community center design

Abstract

Achieving carbon neutrality in the building sector requires innovative materials such as cross-laminate timber (CLT), energy-efficient solutions, renewable energy, and advanced building technologies to reduce greenhouse gas (GHG) emissions and enhance efficiency. This study evaluates the carbon mitigation potential of CLT as a nature-based solution (NBS) through substitution scenarios in a small-scale regional community center. The process begins with identifying potential building materials and a baseline model using traditional concrete. CLT is integrated as a hybrid material for walls and floors, substituting concrete in varying ratios to evaluate the life cycle carbon emissions and energy efficiency improvements. Key stages of the life cycle assessment (LCA) include material production, construction, operation, and end-of-life. Substituting concrete with CLT reduces GHG emissions by up to 9.22%, with the product stage showing the highest potential for carbon mitigation. The use stage also demonstrates significant reductions owing to the superior thermal performance of CLT, particularly in terms of operational energy consumption, where heating accounts for 88% of the energy savings in cold climates. Additionally, the study highlights the benefits of extending building lifespans and integrating renewable energy during the operation phase. Hybrid CLT buildings with higher exterior substitution ratios, as seen in scenarios S3-1 and S3-2, exhibit notable improvements in energy efficiency and life cycle emissions. Unlike previous studies, this study provides a focused analysis of the substitution rates, serving as a foundation for future large-scale timber construction. Continued research on detailed assemblies and optimized low-carbon designs is essential for advancing sustainable high-rise timber construction.