As BIM diffuses into different aspects of the architecture, engineering, and construction (AEC), the conventional project practices have been disrupted. In particular, projects experience a few obstacles and challenges to integrate BIM into the AEC process. This leads to hybrid AEC practice with BIM and non-BIM information processing. Such a situation can be chaotic with the institutional changes accompanied by the implementation of BIM in AEC projects. Focusing on this issue, the current study aims to identify BIM-invasion modes to AEC projects and contextualize the institutional changes in BIM-based construction. Initially, the possible institutional changes are identified and a theoretical framework to contextualize them is proposed through the review of literature. A following case study compares two projects with different BIM-invasion modes, captures the institutional changes, and verifies the theoretical framework. The case study also validates the major institutional elements related to BIM and demonstrates two BIM-invasion modes to the AEC projects. This research explains how the AEC project changes from an institutional perspective with the systematic implementation of BIM and provides implications to its organizational management. The primary implication is that the extensive use of BIM in AEC projects shall ensure that institutional changes are manageable.