We consider a strictly three-dimensional modeling technique as a basis for numerical simulations. Applications range from · a high-resolution indoor air flow modeling using the so-called thermal lattice Boltzmann method, · combined with a multizone network model for the building energy simulation, · to the scope of structural engineering, i.e. a three-dimensional high order solid finite element analysis of a building. Starting from a building product model described by the Industry Foundation Classes (IFC) standard, we derive an intermediate geometric B-rep model based on the ACIS geometric kernel (Spatial Corp.). This ’consistent’ (e.g. free from gaps) and ’corrected’ (e.g. due to intersections) geometric model is decomposed into a so-called connection model. We describe the analysis and discretization of this strictly volumeoriented model, which serves as the basis for all numerical simulations and thus enables automatic mesh generation with respect to different numerical schemes. A database manages additional attributes and the relation between IFC and ACIS objects. The last section sketches how structural simulation and thermal building simulation can be embedded into a common simulation environment.     «

We consider a strictly three-dimensional modeling technique as a basis for numerical simulations. Applications range from · a high-resolution indoor air flow modeling using the so-called thermal lattice Boltzmann method, · combined with a multizone network model for the building energy simulation, · to the scope of structural engineering, i.e. a three-dimensional high order solid finite element analysis of a building. Starting from a building product model described by the Industry Foundation Cl...     »