This paper presents a graph-based data management approach for automatic transformation and linking of BIM models with further domain models. The BIM transformation is based on IFC standard and covers both of IFC schema and IFC models. The aim of this research is to demonstrate the potential of graph theory concepts and applying a graph database framework for analyzing, managing and visualization the complex information and relationships inside BIM models and in particular to use this information to connect the BIM model with external models generating multimodels, i.e. a linked data set. It is demonstrated that graph-based approaches is an excellent alternative to current approaches which are based on traditional SQL databases and usually limited to query single BIM models. For validation of the approach and demonstration purpose, a set of advanced queries for data retrieval, compare, classification are shown. Also, a prototype web application with simple GUI is also developed for easy access of the connected graph model.