## 5 Results and Discussion
### Open-Ended Interview Theme Analysis
#### 5.4.1 Effectiveness  
All participants (\(n=15\)) believe that BIM and VR-integrated technology effectively enhanced the quality of the design phase in prefabricated building projects, which was mainly reflected in three aspects:  
1. Improvement of Design Tools. Participants (\(n=12\)) believed that this method optimized the 2D drawing output process, enabling the automatic export of detailed component drawings, construction node details, design annotations, and other complex drawings. This method also enhanced the accuracy and precision of prefabricated building design drawings, aiding in comprehensive quality control of design drawings at the design phase. Participants (\(n=8\)) expressed that project stakeholders could effectively select different design outcomes per their needs, enhancing the comprehensiveness and objectivity of the final design review and providing a solid foundation for project communication in subsequent construction and operation phases. Participants (\(n=3\)) mentioned, \"This method requires BIM model data to support import, reading, conversion, and output functionalities, demanding richness, integration, and uniformity in model data. This will stimulate the number and scope of collaborative design software, supporting collaborative design development in the prefabricated building.\"
2. Optimization of Workflow. Participants (\(n=11\)) believed that the design environment created by BIM and VR-integrated technology provided a platform for real-time design participation and immersive virtual reality experiences for all project stakeholders and the public. This enabled different roles to fully engage in the design process, offering real-time feedback on professional opinions and fostering the development of multi-threaded workflows. Therefore, it avoided common issues in traditional design methods, such as frequent design conflicts, lengthy coordination meetings, delays in design change communication, and significant discrepancies between drawings and models, severely affecting the quality and efficiency of prefabricated building design.
3. Shift in Design Thinking. Participants (\(n=8\)) believed this method had led to a shift toward holistic thinking and a lifecycle awareness among designers. Specifically, in the early design phases, when a virtual site was created, the designers would take environmental factors (e.g., sunlight, sound, and wind) into account to propose project planning solutions; in subsequent phases like scheme design, preliminary design, and construction drawing design, there was a continuous \"communication-dialogue\" with the architecture, finalizing design contents based on real human experiences and refining the design proposals. After the design proposals were completed, the integration of models, simulations, and immersive experiences was used to test the feasibility of the plans to select the best building materials and interior design furniture, focusing on user experience feedback. Participants (\(n=5\)) also mentioned that the design process now included simulations and considerations for construction feasibility and operational maintenance, contributing to the lifecycle development of prefabricated buildings.