One of the biggest reasons for productivity losses on construction sites is site congestion. Conflicting workspaces designated for resources: labor, material, or equipment, lead to productivity losses at best and safety incidents at worst. Several factors affect the intensity of overlapped space on site, including the volume of the overlapping workspaces and the importance of the conflicting activities. This project aims to investigate how modular construction can present a new approach to reducing site congestion in time-sensitive projects. A case of a fast-tracked residential building was used to evaluate the magnitude of site congestion on construction progress. The case study project had to comply with the difficult owner’s criteria, which included a small site accessibility area and a two-week building timeframe. The clashes between the resources that were placed on the site were examined using a 4D simulation program. The simulation examined the workspace overlap volume that was then integrated with the activity criticality and safety considerations to determine the intensity of the collision. An initial review of the construction plan and a conflict resolution process for changes in sequence led to unacceptable project schedule delays past the intended completion date. In order to shorten the entire project time and fulfil the needed project deadline, innovative construction approaches were used to shorten activity durations and the number of clashes. In time-sensitive, fast-tracked projects, prefabricated building is presented in this study as a useful strategy for resolving clashes. The added benefit of altering the construction method in conjunction with a change in sequence as a productive clash resolution technique is also highlighted in the paper.