This study aims to integrate BIM/GIS to detect indoor navigation routes, where these routes are simulated afterwards via connecting such information into a gaming environment. For testing these developed concepts, some sections of the Istanbul Technical University, Faculty of Civil Engineering building are modelled utilizing the BIM concepts. The designed methodology includes generating the BIM model, transforming the model into international standard Industry Foundation Classes (IFC) and again transforming this into FBX format to work in Unity platform that is a gaming environment. Furthermore, these processes are bi-directional. The final deliverable enables the user to navigate in the faculty building via a three-dimensional BIM-based environment. Via the described concept, easy, repeatable and reliable three-dimensional information is achieved that is the initial step for smart cities.