The creation of BIM models is a critical step in implementing BIM technology effectively. However, there is currently a widespread issue of indiscriminate use in BIM modeling and design detailing. Therefore, it is essential to standardize design documentation during the bidding phase, which can be highlighted in the following key areas:
① Achieving a certain level of depth and precision in BIM models forms the basis for developing accurate bidding control prices. The arrangement of pipelines, walls, equipment, and other elements across various disciplines greatly influences the quantities of materials and equipment required. For example, in installation work, frequent clashes occur between air ducts, cable trays, HVAC pipes, fire water pipes, and drainage pipes—especially in large-scale infrastructure projects where these conflicts can be more severe. Adjusting the spatial layout of these components significantly impacts material quantities and, consequently, the bidding control price. Moreover, establishing a detailed model early on supports clear division of responsibilities among different professional construction teams and facilitates better construction planning and resource allocation during later stages.
② BIM modeling standards greatly affect the accuracy of subsequent bidding control price calculations. Due to long-standing design habits, some professionals may struggle to adapt when using BIM technology for 3D modeling during the design phase. They might rely on previous modeling practices, resulting in components that do not conform to software format requirements. This leads to software being unable to fully read component information, causing significant discrepancies when extracting quantities. Therefore, early modeling is a crucial step in the BIM process. Component classification and naming conventions should be established according to software capabilities and relevant standards to ensure accurate data reading and transmission.
③ Ensuring data exchange integrity is essential. Ideally, building a 3D model early on based on relevant standards should allow direct extraction of engineering quantities through the bill of quantities. However, challenges remain at this stage. On one hand, BIM technology’s cost management data in China is not yet fully developed. On the other hand, interoperability standards and formats between various software platforms still have limitations. Automatically generated quantities from software often do not align with China’s pricing standards, which differ in their pricing rules. Thus, it is necessary to establish standards during modeling to retain relevant building model information when importing into cost software later. This helps prevent inaccurate quantity calculations due to missing components. Although many cost management software now offer plugins to maintain data integrity between BIM models and costing tools, establishing consistent component overlapping and naming rules during BIM model creation is even more important. For instance, type information for custom-built families is often overlooked or hard to define during modeling, which complicates recognition when importing into cost software and results in incomplete model imports. Assigning standardized names to these components allows cost software to identify them through semantic data, match them with inventory and quota databases, and accurately perform measurement and pricing.
④ Currently, there is a significant lag in BIM modeling and detailed design. BIM has yet to fully address the accuracy and standardization of design documents in early project stages, nor has it effectively designed spatial layouts within and across different disciplines. This represents an abnormal state in BIM implementation. Moreover, serious problems arise during construction phases involving BIM formwork flipping, clash detection, and detailed design. Due to limited BIM application depth and fast construction schedules, BIM-based clash detection and detailed design often fail to provide meaningful guidance during construction. As a result, construction teams rely heavily on their own experience rather than BIM insights. Therefore, having a BIM model that has undergone clash detection and detailed design is essential for accurately calculating bidding control prices.
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