BIM models are always subjected to different types of changes and modifications across project development phases. Starting from the early design until the handover. Normally, the elements of a BIM model change continuously due to several factors such as applying changes in the structural design, changes in the conceptual design, demand for higher LOD during various stages of the project and many other factors making it difficult for project coordinators to document and identify those changes. The lack of version control between different versions of BIM model can create huge gap between different parties involved in the project regarding coordination and collaboration which leads to huge delays and extra costs at the end. The aim of this research is to evaluate different approaches for the comparison of geometry stored in BIM models independent of the way the geometry is represented to apply the concept of version control so that, any modification regarding geometry between model versions can be reported and documented to enhance coordination tasks. Two approaches for geometry comparison will be discussed in this research from the concept and the implementation until evaluation of results and limitations. First approach is based on assembling bounding boxes for elements and comparing them to identify the geometric changes encountered. Second approach is based on generating triangulated mesh for elements to retrieve the list of vertices that describes the geometry of each element then comparing them to specify the changes. At the end, experiments were held on test models provided by Zilch + Müller Ingenieure GmbH to evaluate the accuracy of those approaches in terms of results and to identify the limitation of each approach.     «

BIM models are always subjected to different types of changes and modifications across project development phases. Starting from the early design until the handover. Normally, the elements of a BIM model change continuously due to several factors such as applying changes in the structural design, changes in the conceptual design, demand for higher LOD during various stages of the project and many other factors making it difficult for project coordinators to document and identify those changes....     »