The embodied air pollutant emissions and water footprints of buildings in China: a quantification using disaggregated input-output life cycle inventory model

Building has complex supply chains involving different sectors in a national economy. Although input-output life cycle inventory (I-O LCI) model enables economy-wide footprint calculations, the model is vulnerable to sector aggregation and is thus unsuitable for individual product analysis. This study employed a disaggregated I-O LCI model that divides the construction sector in China into thirteen building sub-sectors to fill the national inventory data gap in building embodied emissions and water footprints. Results show that public buildings have larger footprints than residential buildings because of their heavy structural designs that significantly depend on steel and cement consumption. Compared to rural residential buildings, the footprints of urban residential buildings are 55-130% greater. Materials efficiency enhancement is a promising pathway to building embodied footprints mitigation and the use of an applied technology-the near net shape casting-would offer China an annual greenhouse gas (GHG) mitigation potential of 5.2 million metric tons of CO2e. This study presents complete and specific calculations for building embodied emissions and water footprints in China. Study results fill the existing national data gap, facilitate analyses of building embodied footprints mitigation strategies, and contribute to complete building life-cycle impacts studies.