Eksplorasi quantity take off (QTO) dan dampak terhadap biaya berbasis 5D BIM

Abstract

The digital era has driven significant transformation in the construction industry, particularly in addressing cost estimation inaccuracies that often lead to overruns. This study investigates the implementation of 5D Building Information Modeling (BIM) as an innovation in construction cost planning by integrating Autodesk Revit for 3D modeling with Bexel Manager for real-time cost analysis. A case study was conducted on the Tanjungkarang Polytechnic Hall Building project, valued at IDR 8.4 billion and modeled at Level of Development (LOD) 350. A collaborative workflow was employed by converting Revit-based geometry into IFC4 format for 5D analysis in Bexel Manager. The cost data were based on AHSP 2022 and regional SHBJ standards to ensure national compliance. The 5D BIM implementation resulted in a total project cost of IDR 7.344 billion, reflecting a 12.80% cost reduction (IDR 1.077 billion) compared to conventional estimation methods (data project). Major cost variances were found in earthworks (18.55%) and roof structures (34.33%), primarily due to discrepancies in quantity take-off volumes. These differences stemmed from varying levels of detail and modeling perspectives. The system also automatically detected 24 clashes among 330 elements, highlighting issues such as an unmodeled excavation task, misinterpreted foundation task components, and insufficient detail in reinforcement and roofing. Overall, 5D BIM significantly improved accuracy, reduced human error, and demonstrated strong potential to support Indonesia’s digital transformation in construction planning.