Analysis of the Budget Plan (RAB) with the Concept of Building Information Modeling (BIM) in the Banjarbaru At-Taqwa Mosque Development Project

Abstract

In the world of construction, the calculation of estimated costs by planning consultants plays an essential role in the implementation of tenders. The cost estimate calculated by the planning consultant after being reviewed by the authorities will be determined as the owner's estimate (OE) as a reference for assessing the fairness of the price to set the highest limit for a valid bid (Malik, 2013). Inaccuracy in calculating the volume of this work will impact cost overruns if the computed volume is too large and a decrease in building quality if the estimated volume is too small. However, with the development of technology, the volume of work can be calculated quickly and efficiently with the application of Building Information Modeling (BIM). This research will raise the comparison of BIM-based cost estimation with manual cost estimation calculations for the structure of the Banjarbaru At-Tawqa Mosque building.

Building structure modeling includes modeling mountain stone foundations, concreting, reinforcement, formwork, and walls. Modeling using Tekla Structures software with the South-East Asia environment referring to the plan drawings. The output of this model is directly in the form of estimated structural work costs, while the At-Taqwa Mosque Development management team has calculated manual cost estimates. The unit price of work used in calculating the estimated cost refers to the AHSP/HSPK for the City of Banjarbaru in 2022.

From the analysis of the two cost estimates, a very small comparison of the difference in costs is produced. The difference between manual cost estimates and BIM-based cost estimates is 25% for rock foundation work, 5% for concrete work, 9% for reinforcement work, 11% for formwork work, and 8% for wall work. Based on these results, it can be said that BIM-based cost estimation is reliable because it produces cost estimates that are more efficient and not far from manual

Keywords: BIM-based cost estimation, Tekla Structures, Building Structures