Lifecycle carbon footprints of buildings and sustainability pathways in China

The Paris Agreement, with a 2 °C temperature increase baseline and a 1.5 °C target temperature increase, imposes challenges to the sustainability of buildings. However, as an end-user or end-of-the-art, the building sector overlaps with other sectors, such as industry and transportation in building materials manufacturing (such as steel, concrete, cement, etc. ) and electricity use (such as building-to-vehicle charging), imposing difficulties in lifecycle carbon footprint quantification in buildings. In this study, the lifecycle carbon footprint of buildings and sustainability pathways in China are provided. Tools and platforms for lifecycle carbon footprint quantification in buildings are reviewed. A global database for lifecycle carbon footprint quantification in buildings is reviewed and compared, together with an analysis of the advantages and disadvantages. Furthermore, decarbonization technologies in the building operation stage are comprehensively reviewed, including the decarbonization potential, technology readiness level (TRL), techno-economic performance, and current technical status. Pathways on carbon neutrality in building sectors in China are provided. The results indicate that inconsistencies in global databases, unclear definitions of lifecycle carbon emissions, and inaccurate models of building energy consumption are the main challenges for accurate lifecycle carbon analysis in buildings. Various carbon neutrality transformation technologies can be classified into ultralow energy building and near zero-energy building technologies and into efficient heat pump and smart metering technologies. Pathways for low-carbon transition in building sectors include building energy saving (330 million tCO2 with 22%), renewable energy supply (299 million tCO2 with 20%), building electrification and power sector decarbonization (450 million tCO2 with 30%), and carbon capture, utilization and storage (CCUS) technology (420 million tCO2 with 28%). These research results can pave the way for upcoming studies on the lifecycle carbon footprint in buildings and sustainability pathways in China.