Analyzing The Life Cycle Environmental And Economic Performances Of The Renovation Strategies Of The Urban Residential Building Stock

After decades of high-speed development,the Chinese urban construction is slowing down.Planning for the renewal of the built environment has become major concern in China's urban development.Previous studies related to energy efficient retrofit of the existing building stock mostly focused on operational energy reduction either on individual building or on the national and urban level.The evolution of the urban building stock in a resource conservation perspective needs to be further studied.The material and monetary investment and the embodied energy and carbon of building refurbishment need to be examined.However,the life cycle inventory data for reference buildings need to be refined based on thorough case studies.In this paper,the Hongshunli community at Hebei district in Tianjin is picked as the study case.There are a large number of old and a part of historic buildings,among which most of them need to be repaired,renewed or demolished as time goes by.Through field investigation and data collection,the study summarize the characteristics of different stages of energy saving and the history of construction in Tianjin.Based on the characteristics,the years division of residential buildings is decided and four residential buildings built in differernt years are picked as typical buildings.The goal is to achieve 65% and 75% energy saving by proposing an energy efficient retrofit strategy according to the energy conservation design standard of Tianjin.Meanwhile,the heating demand is validated in IES(VE)software whether it reaches the demand of energy-saving target.On the basis of this,a complete Revit model of the building is built to conduct the life cycle assessment with Tally,and add-in for Revit.The result contains the material consumption,ecology and costs indexes of the typical buildings during the life cycle stages of energy saving renovation,operation,and demolition,providing accurate and complete background data for the existing tool named FRASIM.At last,put forward possible scenarios for energy efficient retrofit and get the results of simulation in FRAGSIM.Through comparisons with the results,advise the best scenario during updating the urban building stock.