Life cycle carbon constraint method of green building integrating climate zones, building types, and star ratings

Green buildings are important carriers for carbon reduction in the construction field. However, the existing green building assessment system mainly focuses on energy consumption indicators and lacks constraints on carbon emission. To address this gap, this study proposes a novel method to determine life cycle carbon emission constraints for green buildings, considering climate zones, building types, and star ratings. First, a representative sample database for China's five climate zones was developed using probability distribution functions and Latin hypercube sampling. Second, a life cycle carbon emission calculation model was established in combination with EnergyPlus building performance simulation to obtain emission data of 3,500 samples. Finally, K-means clustering was performed on the carbon emission data of these samples to determine the carbon emission constraint values. Results show that operational (median: 50-73 %) and production phases (median: 25-47 %) jointly account for >90 % of emissions across all samples, highlighting the insufficiency of considering operational emissions alone. Notably, thresholds vary significantly: Three-Star residential buildings in severe cold, cold, hot summer and cold winter, hot summer and warm winter, and mild zones have life cycle limits of 45.7, 40.3, 32.7, 28.1, and 24.2 kgCO_2e/(m²⋅a), while Three-Star office buildings exhibit 48.5, 50.7, 46.1, 36.4, and 34.5 kgCO_2e/(m²⋅a). This provides a scientific basis for settig differentiated carbon reduction targets for various green building types. © 2025 Elsevier B.V.