Quantification and spatial pattern of embodied CO2 footprint of prefabricated buildings in urban agglomerations: A case study of Beijing–Tianjin–Hebei, China

Abstract

Prefabricated buildings (PBs) boost a productive and sustainable construction industry transition and can influence the carbon footprint of the construction sector. With China's continued urbanization, an expanding PB sector is foreseeable, exerting substantial carbon dioxide (CO2) mitigation pressure. By using the Chinese Industrial Ecology Lab technology, we developed a hybrid multi-regional input‒output model that integrates a bottom-up inventory of building materials into China's 2017 economic system to quantify PB-embodied CO2 emissions in the Beijing–Tianjin–Hebei urban agglomeration. Two structural types (shear wall and frame-shear wall) with four prefabrication rates (15%, 30%, 50%, and 60%) were considered. The results showed an average of 756 kg/m2 PB-embodied CO2 emissions in the urban agglomeration, with Tianjin (488 kg/m2) and Zhangjiakou (1271 kg/m2) showing the lowest and highest values, respectively. Approximately 60% of PB-embodied CO2 emissions were generated within the urban agglomeration, and Tangshan, Handan, and Zhangjiakou were the major contributors. The PB-embodied CO2 footprint was dominated by electricity and heat generation (42%), non-metal mineral products (27%), and metal smelting and processing (15%). The results revealed the spatial pattern of PB-embodied CO2 footprint in the Beijing–Tianjin–Hebei urban agglomeration and identified key emission sectors in the PB supply chain, contributing to low-carbon PB delivery in China.