Environmental Impacts of Prefabricated Construction: CO2 Emissions Comparison of Precast and Cast-In-Place Concrete Case Study

Abstract

Construction activities are one of the major contributors to climate change by greenhouse gas emissions. While the use of prefabrication has certain advantages in terms of environmental impacts through material and time efficiency, it is not clear nor has enough data for the quantities and factors comparing the conventional methods. This study aims to review the characteristics of prefabricated construction and to find environmental impacts through the case study. The methodology is the analysis by comparing the carbon emissions of precast concrete which is one of the major prefabricated structures and cast-in-place concrete which is conventional methods. The case study data is based on residential buildings which were built by prefabricated structures in South Korea. The comparison is conducted focused on several scenarios according to the criteria for precast concrete construction such as loss rate of materials, delivery distance, vehicle capacity, equipment types and installation hours. The outcomes are found that the amount of carbon emissions of precast and cast-in-place concrete for the studied residential buildings. Based on the research findings, it is recommended to adopt precast concrete in building construction in terms of environmental impacts during the product stage and construction stage. However, these averages can be a significant variation among individual projects. The far distance, small vehicle capacity and low efficiency of equipment with a loss of material can adversely affect the environment. The building industry should consider the carbon reduction as a benefit of implementing prefabricated construction after considering the characteristics of the location, distance, transportation method, and installation efficiency.