## 6 Conclusions  
The construction of reaction walls in structures laboratories poses significant technical challenges due to their structural complexity and stringent performance requirements. By implementing the virtual design and construction (VDC) methodology, this study demonstrated a systematic approach to improving project planning and execution, achieving a more accurate and effective construction process. The VDC framework, supported by its core components--building information modeling (BIM), integrated concurrent engineering (ICE), and project production management (PPM)--allowed for the successful alignment of project objectives with client expectations. In the PPM component, the methodology aimed to identify priority construction processes by mapping critical tasks and releasing restrictions, enabling smooth progression through each project phase. The initial Gantt chart estimated a 38 day timeline. However, due to the complexity uncovered through detailed simulations and ICE sessions, this timeline was revised to 45 days. This extension was justified as VDC provided a realistic depiction of the required tasks, reducing risks related to scheduling inaccuracies and enhancing constructability. This conclusion supports findings from previous studies, which suggest that VDC contributes to more precise scheduling and greater predictability in complex projects [6]. The BIM component was instrumental in reducing project risks by addressing over 250 design inconsistencies identified during the initial stages of the project. By utilizing 4D BIM, project teams could visualize construction sequences, reducing the potential for construction errors and reworking. This aligns with the existing literature on the effectiveness of BIM in optimizing project visualization and inter-team communication, as well as its impact on reducing timelines in construction projects [22]. The improved coordination also enhanced the ICE component's efficacy, where construction sequences were validated through expert consultation, resulting in a 100% validation rate. This iterative approach ensured that all stakeholders were fully informed and prepared, improving decision-making speed and accuracy during the ICE sessions. The study findings also align with the observed benefits of VDC in broader applications within the architecture, engineering, and construction (AEC) industry, particularly in enhancing collaborative work environments and improving project efficiency [19]. Moreover, implementing VDC for a specialized project like a reaction wall--a small-scale yet highly detailed structure--demonstrates that the methodology can be applied effectively beyond large infrastructure projects. This expands the existing body of research on VDC, primarily focusing on high-scale construction projects, by highlighting its applicability and benefits in more intricate and specialized construction environments. The survey among project stakeholders showed strong acceptance of the VDC methodology, with 93.3% of participants acknowledging the methodology's role in resolving construction incompatibilities and enhancing understanding of the construction process. This high level of acceptance, coupled with the willingness to adopt VDC in future projects, reinforces the methodology's user-friendly nature and suggests a positive learning curve. These findings echo similar sentiments in the literature advocating for VDC's integration into construction workflows to foster collaboration, streamline planning, and optimize project outcomes [24]. In conclusion, the application of VDC in this study not only facilitated a successful construction outcome for the reaction wall but also provided a comprehensive framework for project planning which is transferable to other construction projects of similar complexity. Future research could expand on these findings by implementing VDC from the design phase to maximize its benefits and assess its impact across different construction types.