When implementing BIM in your organisation or in a specific project, different concepts can be distinguished and summarised with the terms open BIM (or fully collaborative BIM) and closed BIM (or “lonely” BIM).
In general terms, open BIM describes a design environment in which different project participants using different BIM software solution share and integrate their models and data with each other using non-proprietary file formats, including IFC (Industry Foundation Classes).
On the other hand, closed BIM refers to a relatively restricted design environment in which all participants use a single BIM software platform.
In general, the main benefits of BIM can be generated when using open BIM: It allows project members to participate regardless of the software solution they use and provide enduring project data for use throughout the asset life cycle, avoiding multiple input of the same data and consequential errors.
Deciding whether to work with open BIM or closed BIM depends on several key variables, including the size of the project, which performance parameter of BIM are to be used in the project (e.g. use of 5D; linking BIM to software for tendering or the Facility Management), fixed requirements of the client in regard to the use of the software, the diversity of all project participants, the platforms that the respective disciplines favour for implementing BIM and whether the project needs to maintain data for the whole life cycle (such as facilities management).