Study On Building Life Cycle Carbon Emissions Prediction Model

Construction-related carbon emissions have exceeded one-third of total carbon emissions in China.Reducing carbon emissions from buildings has already become a trend of development.Research on building carbon emissions is also imperative.However,the current accounting methods for building carbon emissions are complex and require large number of data for support,which is difficult to effectively use in low-carbon building design.This research was funded by the National Key Research and Development Program of China?Grant No.2016YFC0700201?,aimed to study on assessment and prediction model for life cycle carbon emissions.Firstly,this paper reviewed the literatures from home and abroad,and LCA theory,researched on the accounting methods of lifecycle carbon emissions from buildings,including system boundary,inventory model,activities analysis and data sources.And the importance and assessment scope of lifecycle carbon emissions from building materials were discussed.At the same time,methods of carbon emissions assessment in some green building evaluation standards were given,and analysis of building performance simulation softwares for operation phase were given,too.Based on environmental impact inventory data in the relevant standards and papers,carbon emission factors of main energy sources,building materials,transportation and machinery&equipment were determined.The building life cycle was divided into four stages:manufacture,construction,operation&maintenance,disposal&recycle,and the carbon emission accounting model was given.The life cycle carbon emissions accounting model for building materials was given meanwhile.Lifecycle carbon emissions of 207 residential buildings in Tianjin were then counted.Results show that annual carbon emissions per floor area are between 30 and 60kg CO₂/?m²·year?in this cases study,and phase of operation&maintenance has major share?75-87%?in life cycle carbon emissions followed by materials production?11-25%?,among which steel,concrete and mortar produce the largest carbon emissions,accounting for more than 80%.According to results of lifecycle carbon emissions assessment for building materials,significant factors of carbon emissions from building materials were determined by methods of simple correlation and partial correlation analysis.Then the linear and nonlinear regression methods were used to construct the prediction models respectively and accuracies of those models were verified.According to results of life cycle carbon emissions assessment for buildings,scatter plot and collinearity diagnosis were used for data pretreatment,then simple correlation analysis and elastic net were used to determine 12 significant factors for prediction model.Lastly,PCR,RF,MLP,SVM were used to construct prediction models respectively,comparison and discussion of those models were given in the end.Based on the relatively complete accounting model for lifecycle carbon emissions,this paper has realized the prediction of the carbon emissions from building lifecycle.Research results in this paper not only provide the possibility for architects to estimate lifecycle carbon emissions of buildings at the initial stage of design,but also provide reference and practical guidance for the subsequent research on building carbon emissions.