BIM-Based Incremental Cost Analysis Method of Prefabricated Buildings in China

Abstract

In order to achieve the sustainable growth of its urbanization and natural resources, China has been making great efforts to develop prefabricated construction technologies. However, the high incremental cost of prefabricated buildings (PRBs) is a fundamental obstacle to the latter. The current study mainly focuses on analyzing the incremental cost of the on-site construction stage. It is hard to comprehensively identify the incremental cost composition without considering the incremental cost caused by prefabricated components (PFCs) production. Moreover, the results of incremental cost calculation are not accurate enough by comparing the cost of two similar but different PRB and traditional buildings (TRB), and the case-based calculation results suffer from a lack of representation. To address these issues, we first establish a two-dimensional incremental cost index system from the dimension of cost items and prefabricated technologies to study the incremental cost composition of the whole construction stage. Additionally, based on China’s latest policies documents, the applicability of incremental cost composition items can also be improved. Then a building information modeling (BIM)-based calculation model is presented to avoid the calculation error caused by comparing the cost of two different PRBs and TRBs. To validate the proposed index system and calculation method, an actual prefabricated project in China is also conducted as a case study. The results suggest that: (1) Incremental cost is composed of band bearing and retaining walls and inner walls PFCs production, PFCs hoisting and grouting, post-pouring concrete, and full decoration. (2) The BIM-based incremental calculation result of a PRB case from Shanghai is within the range of the national average PRB incremental estimation results. The incremental cost composition items and BIM-based calculation approach can greatly help investors to identify the largest increase in cost and make effective cost optimization strategies.

Sustainable Performance of Buildings through Modular Prefabrication in the Construction Phase: A Comparative Study

“…The evaluation of energy consumption was different than the extant research, which demonstrated there is an obvious energy savings benefit from adopting modular prefabrication [32,61]. According to the case project, electricity and diesel oil consumption in prefabricated residential building construction is higher by 27% and 41% compared with conventional construction, respectively, because electricity consumption increases greatly due to scaffolding and vertical transportation and diesel oil consumption increases greatly due to the trucking required to install protective steel grids and the truck cranes needed to unload prefabricated components.…”

“…Cao et al demonstrated that prefabrication has a clear advantage in material consumption, energy use, and water discharge [28]. In addition, many studies have focused only on one or a very limited number of indicators to discuss the benefit of prefabricated building, for example, waste generation [29,30] and incremental costs or cost savings [31,32]. Tam and Hao pointed out that construction waste was greatly reduced in various on-site activities [30].…”

Evolutionary Game Simulation on Government Incentive Strategies of Prefabricated Construction: A System Dynamics Approach

“…e cost of prefabricated construction is usually higher than traditional cast-in-place construction methods due to the unsound standard system, weak modular design ability, and low efficiency for scale production [11,12]. It is estimated that using prefabricated construction may lead to an incremental construction cost of about 260 CNY per unit construction area (m 2 ) [13,14]. Most contractors are unwilling to adopt prefabricated construction in order to pursue the maximization of economic benefits [15].…”

Creation and Diversified Applications of Plane Module Libraries for Prefabricated Houses Based on BIM

“…It has been widely used in a lot of countries due to the benefits [3]. Prefabricated buildings are also very popular in China [4]. However at present, the floor plan design of the prefabricated house in China still follows the traditional house floor plan design method, and even applies the traditional house plane directly, resulting in problems in the market such as an unreasonable distribution of the suite types of the fabricated house, a low utilization rate of the space of the suite types, an unreasonable plan size with too much variation, a lack of flexibility in the space design, etc.…”