Comprehensive Benefit Of Prefabricated Housing In The Whole Life Cycle

Residential housing accounts for a large part of building products.According to the China Statistical Yearbook,the total output value of the housing construction industry was 12.35trillion yuan in 2016,accounting for 63.82%of the total output value of the construction industry.As we all know,prefabricated buildings can reduce energy consumption,protect the ecological environment,improve the quality of work and life,reduce on-site wet operations,reduce on-site pollution,increase labor efficiency,and achieve civilized construction.This article takes a residential project in Shenzhen as an example to try to study the comprehensive benefit of prefabricated buildings in a quantitative and qualitative manner.Comprehensive benefit includes three branches:economic benefit,environmental benefit,and social benefit.Through combing the literature,it was found that each branch consists of several sub-items,including qualitative and quantitative indicators.Quantitative indicators contain three economic benefit indicators and three environmental benefit indicators.Because social benefit and some indicators of environmental benefit lack of effective calculation methods,they are qualitatively analyzed.In the qualitative analysis,seven economic benefit indicators,five environmental benefit indicators and six social benefit indicators were selected.The index weights were calculated using the analytic hierarchy process.Case study found,comparing with similar houses completed by traditional construction methods,the economic benefit of prefabricated houses is 901.44 yuan/m~2,the environmental benefit is 15.1 yuan/m~2,the social benefit is 0 yuan/m~2,and the comprehensive benefit is 916.54yuan/m~2.The proportion of the benefits of each part to the overall benefit was 98.4%,1.6%and0.In qualitative analysis,the proportion of comprehensive benefit,economic benefit is 67.8%,environmental benefit is 19.2%,and social benefit is 13.0%.The study found that the whole life cycle of a prefabricated housing can be decomposed into the design phase,construction phase,operation phase,and demolition recycling phase.The comprehensive benefits of each stage is-115.98 yuan/m~2?833.03 yuan/m~2?198.36 yuan/m~2 and 1.13 yuan/m~2.Comparing with similar houses completed by traditional construction methods,the comprehensive benefit of the prefabricated housing is negative in design stage.At the construction stage,the comprehensive benefit become positive through the accumulation.In the evaluation of the value measurement method,the top three in the absolute value of the quantification calculation is the period benefit,policy benefit,incremental construction cost.In the evaluation of the analytic hierarchy process,the overall index weights ranked in the top three are policy benefit,construction cost and maintenance cost.The factors affecting the comprehensive benefit of the life cycle of prefabricated housing are analyzed.Key factors include prefabricated component costs,prefabrication rates,on-site construction management levels,and incentives for policies.Based on the above results,it is suggested that various methods such as policy support,research investment,industrial integration,and skills training should be adopted to reduce the obstacles to the development of prefabricated residential buildings and upgrade the comprehensive benefit of prefabricated housing.It is hoped that this study will have a certain reference meaning and reference value for the implementation of prefabricated buildings in China.