Assessment Methodology And Empirical Analysis Of Embodied Carbon Footprint Of Building Construction

In the context of the greenhouse effect and global climate change, countries in theworld in reducing greenhouse gas emissions contribute their strength. In order tomeasure the effect of energy saving, governments and non-governmental organizationsto establish a variety of greenhouse gas measurement and evaluation system. Carbonfootprint (CF) as an important method to measure the greenhouse effect andenvironmental impact assessment, both at home and abroad has been widely used.One third of global greenhouse gas emissions come from the production and use ofbuilding products. Therefore, the building industry is reckoned highly energyconsuming. The construction phase accounts for almost20%of the embodied CF duringthe whole life cycle of building products. However, researches and studies on in thisfield are unsufficient both in amount and depth. Responding to this situation, thisresearch establishes an assessment methodology of embodied CF of buildingconstruction based on "Life Cycle Low-carbon Low-cost Green Building: Policies andRegulations" researching program led by Chinese Academy of Engineering. Also, witha detailed empirical analysis, the generating mechanism of embodied CF of residentialbuildings has been revealed. Conclusions and results are as follows:(1) Engineering quantity and cost measurement systems is proved to be feasible inthe assessment of embodied CF of building products. The process of empirical researchdemonstrates that with the help of a standardized engineering measurement system, abasic database can be built to reflect the industry average or individual production levels.Using software, engineering quantities can be analysed on perspectives of structuretypes, emission factors and work segments to identify and quantify all emission sourceson the producing stage of building. Hence, the result of empirical study can be ofguidance on the reduction measures taken in selecting building structure, materials,design and other important prospects.(2) By collecting, collating and calculating17cases using statistical methods, alow of embodied CF of residential buildings is discovered, concerning the features ofthe three structure types respectively, providing a sound research theory and methods ofembodied CF assessment. More over, the results can be directly applied to practicalresidential building products in their CF calculation and assessment. (3) The empirical results show that90%of the greenhouse gases emitted duringmaterialization phase has their footprint embodied in reinforced concrete engineering,metal structural engineering and masonry works; in the three structure types ofbuildings, the indirect emissions from material production account for94.34%,96.04%and97.05%of total emissions respectively; the total floor area of the building is themost important variable affecting the CF. Therefore, the prediction of CF should beincluding as a factor in the project planning decisions; materials that are critical in thecontribution of total embodied CF should be carefully inspected and selected.