Embodied Carbon of Mass Timber Buildings in the United States: A Systematic Review of Life-Cycle Assessment (LCA) Evidence

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Provides a comprehensive synthesis of LCA evidence on mass timber's carbon benefits and methodological challenges, guiding future research on harmonized carbon accounting.

🏢実務担当者:Offers quantitative benchmarks (10-60% GWP reduction) and methodological insights for corporate sustainability teams evaluating low-carbon building materials.

🏛政策担当者:Highlights the need for standardized LCA methodologies and region-specific data to support building code updates and carbon accounting regulations.

This review synthesizes peer-reviewed life-cycle assessment (LCA) studies evaluating the embodied carbon and global warming potential (GWP) of mid-rise mass-timber buildings in the United States. Prompted by regulatory changes in the 2021 International Building Code that permit taller timber construction, the review focuses on the policy, market, and environmental context. A rigorous, structured protocol incorporated comprehensive database searches, systematic screening, clearly defined inclusion and exclusion criteria, and critical methodological appraisal. 30 peer-reviewed studies were identified that quantitatively assessed embodied carbon, GWP, and biogenic carbon flows in mass-timber systems, typically in comparison with reinforced concrete and steel alternatives. The reviewed literature demonstrates that mass-timber buildings exhibit lower GWP than conventional construction systems. Reported reductions range from 10–20% to 20–60%, depending on system boundaries, functional units, and modeling assumptions. Representative findings indicate cradle-to-gate reductions of 19–41% and cradle-to-grave reductions of 34–51%. Greater reductions are observed when biogenic carbon storage and end-of-life (EOL) recovery or recycling credits are considered. This review critically examines methodological variability across the evaluated studies. Principal sources of divergence include inconsistent system boundaries, heterogeneous functional units, non-standardized biogenic carbon accounting methods, and uncertain EOL scenarios. Regional factors, such as energy-grid composition, transportation, forest management, and climate conditions, further influence outcomes and limit direct comparability. The findings substantiate the embodied-carbon mitigation potential of mass-timber construction while underscoring the need for harmonized LCA methodologies, transparent reporting, region-specific data sets, and improved treatment of uncertainty to inform robust design and policy decisions.

• openalex https://doi.org/10.15377/2409-9821.2026.13.3first seen 2026-05-05 19:11:33