Building Information Model (BIM) is now a well-established notion in the context of built environment management, which includes the construction industry and the facility management industry. At first sight, BIM represents the various tools that support formulation and usage of models of built environments. Vendors that develop and provide BIM technologies typically offer bold promises regarding the positive effects of the usage of BIM. These positive effects include increased efficiency, quality and safety, in the context of the whole lifecycle of a built environment. However, the main emphasis of that rhetoric is placed on the benefits gained from using BIM in the construction and maintenance of new built environments. As the overwhelming majority of built environments are made up of already existing constructions, rather than projected buildings, a key question is: what are the practices for the use of BIM for existing buildings? An explorative research study has been conducted to respond to that question. The main research methods employed included a comprehensive literature review and interviews with BIM experts. The key findings suggested here are: (a) that very little research addresses the actual practices of BIM usage for existing built environments, (b) BIM as such represents a rather complex, multi-dimensional phenomenon, that also introduces new complexities into the lifecycle of built environments, (c) BIM has many stakeholders of which some have conflicting relations with each other; (d) there is a need to conduct comprehensive and independent research into the domain of the use of BIM for existing built environments.