Abstract

: Conventional quantity take-off (QTO) of electrical works relies on two-dimensional drawings and cannot capture the actual three-dimensional routing of feeder cables, cable trays, and cable ladders, causing volume and cost inaccuracy. This research optimizes electrical works QTO using Building Information Modeling (BIM) Cubicost Take-off for Mechanical and Electrical (TME) and implements the validated results into a website-based cost estimation system. Its novelty is an applied, integrated workflow connecting Cubicost TME-based electrical QTO, engineering verification under the General Requirements for Electrical Installations (PUIL) 2020/SNI 0225:2020, and web-based cost reporting within a single Indonesian case study; although each component is established, their end-to-end integration for electrical works is rarely reported. The contribution is a reproducible workflow that converts model-derived quantities into standard-verified, openly accessible cost information, repositioning engineering validation as an integral gate within QTO. Using a quantitative descriptive-comparative method at the BTN Ecopark Gandul project, the installation was modeled three-dimensionally and validated through voltage drop, ampacity, and power demand calculations. On the conventional baseline, BIM-based cable volumes are 8.59% lower with an identical panel count, and the BIM cost estimate is 3.95% lower; all routes satisfy the 5% voltage drop limit, peaking at 1.641%. On an equivalent net basis (after removing the 5% waste allowance present only in the conventional data), the volume deviation narrows to 4.02%, showing that about half of the gross gap reflects the waste allowance and the remainder genuine routing differences; the cost difference is thus an estimated, case-specific figure, not a confirmed saving.