Comparative Study On Material Metabolism And Energy Consumption Of Residential Buildings In Different Scale Cities

City is the external environment of human living,which is inseparable from people’s life.The metabolic capacity of a city is one of the important regulatory functions.With the rapid development of economy,the city burden of material and energy generation and digestion is more and more heavy,the crisis of resources and energy is prominent,the harmonious development of human and nature,ecological environment problems need to be solved.At the same time,the destruction of serious environmental problems will also bring the decline of urban function,which has an important impact on human production and life.Urban construction industry is one of the important industries of economic development,which has experienced rapid changes.As a necessary residence for human life,housing is closely related to people’s living standard.Among them,the construction of residential buildings needs to consume a lot of resources and energy,the consumption of resources is limited,the results can not be ignored.The material metabolism produced in the whole construction process has an important impact on the ecological environment and resource planning,and has a long-term significance for the future urban planning and rational allocation of resources.Therefore,the analysis from the perspective of material and energy metabolism is the basis to solve the ecological environment problems.According to the difference of urban population,the paper selects three cities of different sizes,which are represented by Beijing,Shijiazhuang and Taiyuan.Each city residence is regarded as a system,and the material metabolism process of three urban systems is analyzed by means of system metabolism analysis.The metabolic process is divided into three steps:input,transformation and fixation of building materials and output of construction waste.Then,according to the type of building,the building is divided into two types: brick concrete and steel concrete.Based on the calculation of the consumption of building materials per unit area of different types of residential buildings,the total input and total output of construction waste for the construction of new residential buildings in Beijing,Shijiazhuang and Taiyuan are calculated respectively according to the statistical data of residential area and newly built and demolished area.The main sources of construction waste include the garbage generated by the construction of new houses and the garbage from demolition and reconstruction.Taking Beijing,Shijiazhuang and Taiyuan as the research object,the comparative analysis of material metabolism and energy consumption was conducted in the nine years from 2010 to 2018.Energy consumption analysis analyzes two main stages of building construction and demolition respectively.The energy consumption per unit area is calculated by statistical data,and then the main energy consumption of three cities is obtained.According to the research,Beijing,as the first city,has been in the forefront of urban housing construction since 2010,with small residential change and high cumulative efficiency.Shijiazhuang’s cumulative efficiency takes the second place.Compared with the slow development of Taiyuan,residential floating changes,the cumulative efficiency is low.Energy consumption changes with the increase or decrease of residential area.Through the research and analysis,it provides data support and suggestions for the future urban planning development and management and resource saving in North China.