Comparison of Building Information Modeling and Conventional Methods for Concrete and Rebar Quantity Take-Off

Abstract

Calculation of Quantity Take-Off (QTO) of concrete and rebar must be carried out accurately and consistently. Design modeling also often changes so that technology is needed to simplify and speed up work. The application of Building Information Modeling (BIM) is one way to reduce errors and speed up QTO calculations. One of the BIM software that can be used to carry out QTO work for concrete and rebar is Revit, which is produced by the Autodesk company. The use of Revit is still often encountered obstacles, but these obstacles can be anticipated by conducting an analysis. The analysis carried out include comparative analysis of calculation results, analysis of initial design time requirements and analysis time requirements if there is a design change, and analysis of advantages and obstacles in using Revit. The data was obtained by conducting interviews and calculating the QTO of concrete and rebar using Revit and conventional methods. The results show that the use of Revit is recommended. This is because Revit can speed up the calculation time for the QTO of concrete up to 49% and the QTO of rebar up to 20% for the initial design stage, the calculation of QTO of concrete if there is a design change up to 90%, and QTO of rebar up to 67% when compared to the conventional method. Respondents also stated that they prefer using the Revit method compared to conventional methods. This study shows that there are no difference results for the QTO of concrete and there is a slight difference for the QTO of rebar up to 0.6742%.