The advantages of BIM technology in cost management can be summarized in three key aspects: parameterization, visualization, and simulation. First, BIM modeling is inherently parametric. The properties of basic components within the model are expressed through parameters, allowing the model to be updated simply by modifying these parameters when project changes occur. This updated information is stored within the model and shared in real-time with all project stakeholders via the model file, effectively reducing errors and data loss typically caused by manual information transfer.
Second, BIM technology offers a comprehensive system for classifying and managing attributes. Unique parameters specific to a single project can be set as project parameters, while those commonly used across multiple projects can be designated as shared parameters. Parameters of instance components can inherit values from their respective type families. For example, if the material of a certain beam needs to be changed, modifying the type parameter will uniformly update all beams of that type within the project; alternatively, individual beam instance properties can be modified separately as needed.
Third, parameters within the BIM model can be geometrically calculated. Analysis parameters such as volume and surface area are automatically computed and continuously updated alongside the model.
In summary, BIM models created according to standardized rules enable automatic quantity takeoffs. When design changes or construction modifications occur, BIM replaces the traditional repetitive manual quantity calculations. The visualization strength of BIM lies in its 3D modeling approach. Currently, quantity takeoffs often rely on 2D CAD drawings, which suffer from unclear annotations and component clashes across different disciplines. These issues lead to repeated recalculations when changes arise, making precise cost management difficult.
BIM’s three-dimensional models provide a visual environment for all project participants to communicate throughout the entire lifecycle—from design to construction and into operation and maintenance. Early design phases benefit from clash detection, preventing component collisions between disciplines and reducing subsequent change orders.
The simulation capabilities of BIM are also significant. The 3D BIM model created during design can be shared with the cost management team, who then attach pricing attributes to form a 4D BIM model. By adding construction scheduling and time attributes during early preparation and construction phases, the model evolves into a 5D BIM progress simulation. This enables real-time tracking of project cost changes and supports continuous comparisons between budgeted and actual expenses, enhancing cost control throughout the project.
Although BIM offers many advantages in engineering cost management, several challenges remain for its widespread adoption in cost estimation. Firstly, BIM’s approach to quantity takeoff and pricing differs from China’s traditional bill of quantities method. Secondly, while BIM can automatically generate quantities, the quality of BIM models varies significantly, and China lacks uniform standards guiding BIM modeling.
Thirdly, accurate cost calculations depend on precise BIM quantities, which are influenced by modeling standardization. Manual verification of BIM model attributes is as labor-intensive as remodeling. Developing automated attribute checking methods remains an open research area. Fourthly, the quantity table format, which facilitates cost personnel in data collection and calculation, needs to efficiently extract and store BIM quantity information. Establishing a reliable information exchange system remains a major hurdle for BIM promotion in cost management.
Finally, the inconsistency between BIM quantity calculation and the traditional bill of quantities pricing often leads to discrepancies between estimated and actual costs. Until a quota system tailored for the BIM environment is developed, establishing a clear relationship between BIM-derived quantities and costs continues to be a challenge.
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