Case Study On Life Cycle Energy Consumption And CO₂Emissions Of Green Buildings

Energy saving and carbon emissions reduction of the construction sector has agreat effect on sustainable development. While most prior research has focused mainlyon the operation phase of the building, it’s important to study the energy saving fromthe perspective of the lifecycle of the building. The main purpose of this study is tocalculate the life cycle energy consumption and carbon emissions of typical cases tocompare the differences of between green buildings and normal buildings in China.Firstly, according to the review of the researches on life cycle energy consumptionand CO₂emissions of buildings in recent years, including a detailed analysis of104casestudies across16countries, the models of LCE and LCCO₂have been built. By thecomparison study of a number of commonly used domestic or international buildingmaterials life cycle databases, it is apparent that they vary in presentation of calculationresults on energy consumption and carbon emissions, the biggest error rate reachingabout30%. Then, by using BELES building materials database, to calculate energyconsumption and carbon emissions from the building materials of304building cases,according to the building materials lists collected by the cooperation with manydomestic research institutes and enterprises. Through statistical analysis of thecalculation data, to figure out the influential degrees of different factors including thestructural system, seismic level, building floors, thermal partition and green star level.The results show that building floors is significantly correlated to embodied energy ofbuilding materials and carbon emissions, seismic level and structure type followed. Inmulti-storey and high-rise buildings, embodied energy per unit mass of buildingmaterials and carbon emissions are relatively low.Then, by calculating the life circle energy consumption and carbon emissions of anumber of typical cases among green residential and public buildings, the comparativeanalysis between the green building and ordinary building is performed. Anothercomparative study with the foreign cases is done as well. The results show that the lifecycle energy consumption and carbon emissions in public buildings is about2times thatof residential buildings; life cycle energy consumption of green public buildings is33%lower than the ordinary public buildings,38%lower than the large-scale public buildings. Green residential building is13%lower life cycle energy consumption, but25%higher embodied energy per unit mass of building materials than the ordinaryresidential building, similarly with the characteristics of building carbon emissions andenergy consumption.Finally, the establishment of building materials list database is discussed, and atool for assessing embodied energy in building materials and carbon emissions is built,which has established the foundation for the promotion and application of buildingmaterials life cycle assessment.