Analysis of Life-Cycle Carbon Emission Characteristics of Residential Buildings in"Hollow Villages":A Case Study based on A Multi-Story Residential Building in Guangdong

ZHENG Yuchuan; HUANG Zujian; LUO Hao; SUN Yiheng

doi:10.3969/j.issn.1000-0232.2025.08.006

Abstract：Global warming caused by emissions of greenhouse gases such as carbon dioxide represents a significant issue.In 2023,total carbon emissions from rural residential buildings in China reached 400 million tons of CO2,with a carbon emission intensity of 17.8 kgCO2/m2.Therefore,energy conservation and emissions reduction in rural residential buildings are crucial to realizing the low-carbon transformation of Chinese society.In the past,the emergence of"hollow villages,"the result of China's unique urbanization process,has led to a large number of buildings being abandoned in rural areas,resulting in a massive waste of resources and energy.To explore the characteristics of life-cycle carbon emissions(LCCE)of residential buildings in hollow villages and provide references for low-carbon development planning and emissions reduction design of residential buildings in China,a case study based on a typical multi-story residential building with a reinforced concrete frame structure was carried out in Guangdong Province.First,the building life-cycle was divided with reference to the ISO 21930:2017 building life-cycle staging program.The LCCE of the building and the carbon emissions at each stage were calculated using the carbon emissions factor method based on the recorded data.Furthermore,statistics were compiled in a sectional and itemized manner to identify the carbon emission hotspots,and emissions reduction was calculated specifically for these hotspots.Finally,the calculation results were compared and analyzed with those from global studies of the same type obtained through a literature search.Based on the findings of the case study and insights gained from the literature review,some carbon emissions reduction strategies and implementation pathways were proposed from both policy and design perspectives.The research results showed that the total LCCE of the building is 1077.95 kgCO2e/m2,with embodied carbon emissions(ECE)and operational carbon emissions(OCE)of 682.78 kgCO2e/m2(63.34%)and 395.17 kgCO2e/m2(36.66%),respectively.Compared with existing studies,it was found that because such buildings are"built but rarely or never used"in hollow villages,the proportion of ECE of this building is significantly higher than that of other residential buildings.Through sectional and itemized statistics,it was found that ECE is mainly concentrated in three parts:foundation and basement,main structure,and building decoration,accounting for 24.28%,48.41%,and 24.2%,respectively.In terms of materials,ECE is primarily associated with concrete,steel bars,and fired bricks,accounting for 34.19%,25.74%,and 12.03%,respectively.The total carbon emissions from other materials account for less than 30%of the total.Moreover,the main structure and design were optimized in this study.According to a comparison of multiple schemes,the carbon emissions of brick-concrete structures were the lowest under ideal conditions.It is found from a single-factor experimental comparison that the carbon emissions of latex paint walls,ceramic tile walls,rock slab walls,and wood veneer walls account for 44.52%,188.38%,197.62%,and 29%of those from the mixed approach adopted in this case,respectively.In terms of flooring,the carbon emissions of rock slab floors and wood floors are 136.24%and 83.89%of those from the current ceramic tile floors,respectively.Moreover,the maximum gap in carbon emissions between different decoration schemes reaches 6.8 times.Further simulation indicates that adding a photovoltaic roof can reduce emissions by 65.01 kgCO2e/m2.Considering the high proportion of ECE in residential buildings caused by"hollow villages,"this study puts forward three development suggestions from both policy and design perspectives:controlling the scale of residential buildings to avoid construction redundancy;optimizing building material selection considering multiple factors;developing and promoting the application of wood and bamboo building materials to design projects.Since this case only represents newly completed rural residential buildings in Guangdong Province in recent years,it can only serve as a reference for rural residential buildings in other regions of China.It is necessary to collect more comprehensive and precise data in order to understand carbon emissions characteristics of residential buildings in hollow villages more accurately.