It is required to verify construction costs in all phases of construction project life cycle. Especially, the conceptual or approximate estimation is important to assess the project feasibility and budget planning. However, due to limited information and time, there is an issue concerning low-level reliability of the approximate estimating results. The main objective of this research is to provide 3D BIM collaborative approximate estimating model using detailed as-built information of the previous similar projects. In order to achieve the objective, this research builds standardized floor plan database. Space factors and variable factors are extracted from 3D modeling to apply unique characteristics of the project in approximate estimation. The simulation of the suggested model results in a margin of acceptable error range. This research will contribute to visual communication among stakeholders as well as an efficient approximate estimation.