Comparative analysis and influential factors of embodied carbon emissions across low-rise, multi-story, and high-rise residential buildings in China

Embodied carbon emission reduction is crucial for promoting energy conservation and carbon reduction in residential buildings as operational carbon emissions decline. While previous studies have examined the influence of various building characteristics on embodied carbon emissions, the underlying factors responsible for the observed variations in emissions under different characteristics remain insufficiently explored. Using a dataset of 538 residential buildings in China, this study statistically analyzed the embodied carbon intensities of low-rise, multi-story, and high-rise buildings, with average values of 399.2, 442.9, and 450.1 kgCO_2e/m², respectively. Correlation analysis and significance tests were then used to examine differences in embodied carbon emissions across different characteristic categories. The results revealed that structural form and seismic fortification intensity primarily affected the embodied carbon intensity of structural materials, whereas delivery type was mainly associated with that of decorative materials. The proposed influence coefficients further indicated that concrete was the dominant factor to differences in embodied carbon intensity associated with structural forms and seismic fortification intensity in low-rise and high-rise buildings, whereas steel made a greater contribution in multi-story buildings. Moreover, the analysis of potential carbon reduction measures indicated that low-rise and multi-story buildings with frame structures exhibited the highest reduction potential, with reductions of 13.9% and 15.2%, respectively, achievable through material consumption optimization and transport distance reduction. However, in high-rise buildings, shear wall structures exhibited the highest reduction potential (12.5%). This study provides practical insights into optimizing residential building design from a low-carbon perspective.