[Article] Establishing industry-based benchmarks for embodied carbon in 85 buildings in China

Measuring embodied carbon is not enough. We need to know when a building is using too much of it.

For years, the building sector has become increasingly sophisticated at calculating embodied carbon. But a calculation alone does not tell an architect, engineer, developer, or policymaker whether 250, 300, or 400 kg CO₂e/m² is acceptable. That requires benchmarks.

In our new study, we analyzed 85 real building projects in China across seven building types, using actual material quantities from construction companies. The results show just how much typology matters: average cradle-to-gate embodied carbon intensities for structural materials ranged from approximately 200 to 340 kg CO₂e/m², with office buildings recording the highest mean values. But one result deserves much more attention. Together with Zengfeng Zhao, Chao Pan, Gang Yang, Chenyuan Ji, and Carlos José Massucato, we analyzed 85 real building projects in China across seven building types.

Some of the biggest embodied-carbon decisions are buried underground.

Basements had embodied carbon intensities 1.5 to 4 times higher than above-ground structures. Depending on building type, they represented 43% to 70% of total embodied carbon in our analysis. Yet basements and foundations are frequently overlooked or treated inconsistently in carbon assessments. That is an enormous carbon iceberg beneath our buildings. We also found that concrete and steel reinforcement together account for up to 90% of structural-material embodied carbon. This puts structural efficiency, material quantities, reinforcement ratios, and below-ground design directly at the center of the decarbonization discussion. So we took the analysis one step further: from measurement to benchmarking.

For residential buildings in this dataset, for example, 250 kg CO₂e/m² was identified as a statistical boundary between higher- and lower-carbon performance.

This is not a universal carbon limit. Our study focuses primarily on structural materials within A1-A3, cradle-to-gate, and the dataset is geographically concentrated in China. These benchmarks therefore need regional expansion and validation. But the direction is important:

LCA should not end with a carbon number. That number should inform a design decision.

The next step is moving toward building-type-specific, regionally grounded carbon budgets that designers can use before the building is built, not simply to document its impact afterward. The paper contributes to a broader move toward data-based embodied-carbon benchmarks and limits in China.

Should every building project start with an embodied-carbon budget, just as it starts with a financial budget?

Zhao, Z., Pan, C., Yang, G., Ji, C., Massucato, C. J., & Attia, S. (2025). Establishing industry-based benchmarks for embodied carbon in buildings: A statistical analysis of 85 case studies in China. Journal of Building Engineering, 114, 114372.

📘 Full article: https://hdl.handle.net/2268/336694

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