A growing number of research works, experiments and applications is investigating the potential at the intersection of augmented reality (AR) and the architecture, engineering, and construction (AEC) industry. Project management, project communication, collaborative design, maintenance and construction progress documentation, construction site safety, and training are some of the cases that can benefit from blending real and virtual views through mobile devices. In recent years, research also highlighted how mixed reality and building information modeling (BIM) could cooperate to provide effective communication between multiple agents and closer interaction between digital information and the building site. Nevertheless, consolidated applications in these fields are still limited, especially when compared to other areas of AR adoption. This paper presents the development of an AR-based mobile app for exploring telecommunications tower sites and interacting with a related BIM database. The project aims to provide easy-to-use tools to maintain both the physical assets and an up-to-date model. We discuss critical issues in developing a scalable and interoperable application, supporting the feasibility study of similar solutions in the AEC sector.