Considering the complexity and uniqueness of China’s bill of quantities pricing rules, current BIM quantity measurement methods and pricing bases differ significantly from those used in China. These existing approaches are mostly based on foreign BIM pricing software concepts. Furthermore, current BIM models do not fully capture the specialized knowledge required for China’s bill of quantities pricing, such as construction technologies and methods. Developing a BIM-based pricing model for China faces numerous challenges. After research and analysis, the main issues can be summarized into four key areas:
1. Project Feature Description of Building Components
Existing BIM models primarily focus on representing the geometric shapes and physical properties of building components. However, they often lack detailed descriptions of component characteristics, such as geometric features, material types, construction requirements, and related building methods. In contrast, China’s engineering quantity pricing standards provide comprehensive classifications and detailed descriptions of sub-projects. Consequently, the quantities generated by current BIM models cannot be directly used for construction pricing in China.
2. Generation of Engineering Quantity List Items
BIM models typically list quantity items as simple enumerations of individual components without consolidating or summarizing items of the same type. This approach does not align with the structure of quantity lists used in China, rendering BIM-generated lists unsuitable for pricing purposes. To establish a BIM-based bill of quantities pricing model for China, it is essential to develop methods that enable BIM to automatically generate engineering quantity items consistent with Chinese requirements, thereby supporting accurate pricing.
3. Quantity Measurement and Deduction Challenges
BIM models can accurately calculate quantities for most solid building components. However, due to differences in pricing standards, they struggle to measure quantities for certain solid projects like earthworks. Additionally, BIM models cannot currently calculate quantities for non-solid components that are not directly tied to physical entities. To create a BIM-based engineering pricing model, it is necessary to extend the existing BIM framework by expanding its calculation capabilities and scope, improving the accuracy of quantity measurement.
Regarding overlapping elements such as columns, beams, and slabs, BIM’s measurement methods differ from China’s bill of quantities pricing rules, requiring a reevaluation of how overlaps are handled. BIM can automatically deduct voids, such as doors and windows, but the deduction rules differ from Chinese standards. Implementing China’s measurement rules will require modifying the modeling process and applying relevant computer technologies to support pricing deductions according to Chinese regulations.
4. Standardization of Building Component Names and Measurement Units
BIM models are typically developed based on research from foreign engineering industries, leading to discrepancies in naming conventions and measurement units compared to Chinese standards. China’s bill of quantities pricing standards mandate that items include standardized project codes, names, calculation rules, and measurement units. To develop a BIM-based pricing model suitable for China, it is crucial to integrate these naming and unit standards during model construction and calculation. This involves using semantic computing technologies to standardize sub-item projects and incorporating measurement rules for units such as area, volume, length, pieces, and items within the BIM model.
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