The Synthetic Evaluation Of Renewal Scheme For Urban Old Residential Buildings Based On The Value Engineering

From 1980s to 1990s,China had used a lot of manpower and materials in urban multistorey housing development in order to solve the problem of shortage of urban housing.This kind of residential buildings has been built for 30-40 years.Affected by many factors,such as congenital conditions,physical aging,man-made,natural disasters and so on,those buildings have become obsolete,backward,energy-hungry.which are difficult to meet the growing residential demand of residents.In accordance with the requirements of the 14 th five year plan and the local conditions,we will strive to basically complete the task of rebuilding the old urban residential areas which were built before the end of 2000 by the end of the term.It is imperative to adopt comprehensive retrofitting or demolition-reconstruction for the old residential buildings with huge stock and not reaching the design service life.Urban old residential renewal will face four major problems,that the renewal scheme is feasible,the residential building performance can be improved after renewal,the renewal can meet the requirements of sustainable development,and the cost of the renewal scheme is economic and reasonable.Therefore,it is necessary to evaluate the renewal scheme of the old residential buildings in the architectural planning stage.Value engineering as a method of combining technology with economy has the characteristics that research the total life cycle of project from the perspective of technology,function and economy after renewal.It plays an important role in the early decision-making stage of the project,especially in the design stage,A simple and feasible quantitative evaluation method reflecting objective facts is provided for optimization and decision-making of renewal schemes.Firstly,Based on the investigation and analysis of the status quo and renewal scheme of the urban oldresidential buildings,combined with the existing residential performance evaluation standards and related studies at home and abroad,this paper establishes the function evaluation index system of single renewal scheme of the urban old residential buildings,and constructs the functional comprehensive evaluation model based on ANP-fuzzy evaluation.The function coefficient of value engineering is obtained by evaluating the renewal scheme from its function,construction feasibility and environmental and social impact.Then the cost estimation model of the urban old residential buildings’ renewal schemes based on the theory of LCCA is constructed,the economic analysis of the renewal scheme is carried out,the corresponding cost coefficient in the value engineering is obtained,and the value coefficient of the renewal scheme is obtained by combining with the function coefficient.Finally,through the case study of an old residential building in Dalian,this paper verifies the operability and rationality of the synthetic evaluation model of urban old residential buildings’ renewal scheme.To provide guidance for the decision-making of the renewal schemes.This study is based on the value engineering,analysising the function and cost of renewal scheme at the construction planning stage of urban old residential renewal.Meanwhile this study introduced the theory of LCCA to the evaluation of renewal schemes and combined the value engineering working process with the renewal scheme evaluation process.This paper provides a theoretical basis for the decision of urban old residential building renewal program.