Optimization Method and Case Study of Low-carbon Building Reconstruction under Different Preferences

LUO Pei; FENG Yanshan; CHEN Chen; ZHANG Chengyu; CHENG Xionglei; FU Zheng

doi:10.3969/j.issn.1000-0232.2024.12.007

Abstract：Objective:Existing research on carbon reduction renovation of buildings primarily focuses on the application effect of carbon reduction technologies.However,the impact of user preferences on scheme selection and the inapplicability of schemes due to different budget situations in actual projects are overlooked.Targeted at reducing carbon emission and increment cost for building operation,an optimization method of low-carbon architectural reconstruction path under different preferences was built by combining architectural carbon emission simulation,NSGA-Ⅱ multi-objective genetic algorithm,and comprehensive evaluation of multiple economic indicators.Moreover,the applicability of this method to regions with hot summers and warm winters was investigated. Methods:The optimization method of low-carbon architectural reconstruction path under different preferences is composed of the identification of carbon emission influencing factors,optimization of carbon reduction technologies,screening of carbon reduction technologies,evaluation of technical schemes,and formulation of personalized carbon reduction templates.For the identification of carbon emission influencing factors,a benchmark building model was established by DesignBuilder and the carbon reduction effects after applying various technologies were calculated.Inapplicable technologies were eliminated according to the carbon reduction effect and analysis of technological characteristics.Carbon emission was calculated after refining the remaining technologies to optimize carbon reduction technologies.Multiple equilibrium schemes that meet requirements on carbon emission and increment cost of building operation were screened by the NSGA-Ⅱ genetic algorithm.The Pareto solution set obtained by the optimization algorithm was screened using net present value and carbon reduction rate to screen carbon reduction technologies.In order to evaluate technical schemes,indicators such as dynamic payback periods and carbon reduction rates were employed to assess further the economic and carbon reduction effects of the screened schemes.For personalized carbon reduction templates,the path with the best carbon reduction performance,the path with the lowest unit carbon reduction cost,the path with the best full-lifecycle benefit,and the path with minimum project risk were formulated according to multidimensional evaluations of feasible technical schemes. Results:The optimization method of a low-carbon architectural reconstruction path under different preferences was applied to an office building in Guangzhou.In terms of economy,the minimum incremental cost per unit is 156.55 yuan/m2 among the 13 feasible schemes calculated by the proposed method,averaging 260.19 yuan/m2.Compared with similar projects,the incremental cost of the technical scheme obtained from the proposed method can be reduced by 65.87％.The average dynamic payback period of the 13 schemes is 23.60 years,with the shortest being 18.43 years.The average net present value is 2.2005 million yuan,and the highest can reach 3.0476 million yuan.With respect to carbon reduction performance,the maximum carbon reduction rate of the 13 technical schemes is 39.04％,and the average value is 36.34％.It significantly improves the carbon reduction rate by 20％compared to the low-carbon reconstruction scheme in the same region.The carbon reduction of different schemes ranges from 12.16 to 15.38 kg/m2,with an average reaching 14.53 kg/m2.Compared with similar projects,the carbon reduction can be increased by 8.28％to 36.95％.According to the economic and carbon reduction effect evaluation results of the 13 schemes,the path with the best carbon reduction performance,the path with the lowest unit carbon reduction cost,the path with the best full life cycle benefit,and the path with minimized project risk are obtained to satisfy different user preferences. Conclusion:Based on the actual case study of an office building in Guangzhou,it is demonstrated that all feasible schemes obtained from the calculation of the proposed methods all have good economic and carbon reduction effects.Through analysis of the economic and carbon reduction effects of these feasible schemes,the path with the best carbon reduction performance,the path with the lowest unit carbon reduction cost,the path with the best full life cycle benefit,and the path with minimized project risk were further put forward for low-carbon architectural reconstruction in regions with hot summers and warm winters. Limitations:The proposed method applies to regions with hot summers and warm winters but fails to cover all climatic regions.Besides,low-carbon architectural reconstruction evolves multiple technologies.This study only investigated some key technologies rather than covering all refined technologies in different directions.