Carbon Reduction Benefits and Economic Performance Analysis of Lattice Structural Systems Utilizing Small-Diameter Round Timber as the Primary Material

To address the imbalance between the “ecological advantage” and “economic benefit” of wooden structure buildings, this study examines two structural construction methods utilizing inexpensive and readily available small-diameter round timber as the primary material. It demonstrates the advantages of these two structural systems in terms of material consumption, life cycle carbon emissions, and economic efficiency. Through the research methods and processes of “Preliminary analysis–Proposing the construction system–The feasibility analysis of structural technology–Efficiency assessment”, the sustainable wood structure technical system suitable for the development of China is explored. The main conclusions are as follows: (1) Employing the preliminary analysis method, this paper examines and analyzes construction cases that primarily utilize small-diameter round timber as the main material. It delineates specific construction types based on the characteristics of small-diameter round timber. Additionally, it technically reconstructs the methodology for utilizing small-diameter round timber. (2) Two lattice structural systems are proposed, leveraging the mechanical properties and fundamental morphological characteristics of inexpensive and readily available small-diameter round timber of fast-growing Northeast larch. The technical feasibility of these two small-diameter log structure systems is validated through simulation analysis of their spatial threshold suitability. (3) This study conducted a comprehensive comparison between the two small-diameter round timber structural systems and the conventional grain-parallel glued laminated timber (Cross-Laminated Timber) frame structural systems. The analysis was performed from three perspectives. As the primary structural material, grain-parallel glued laminated timber frame structural systems exhibits significant advantages in terms of timber utilization per unit area of the structural system. From a life cycle carbon emission analysis perspective, compared to grain-parallel glued laminated timber frame structures, small-diameter round timber structures can achieve carbon emission reductions ranging from 79.19% to 97.74%. Additionally, the unit area cost of small-diameter round timber structures is reduced by 21.02% to 40.42% relative to grain-parallel glued laminated timber frame structures. Consequently, it can be concluded that small-diameter round timber structural systems possess technical feasibility and construction advantages for small and medium-sized buildings, offering practical value in optimizing technical systems to meet the objective needs of ecological construction.