A methodology to automatically generate geometry inputs for energy performance simulation from IFC BIM models

Building Energy Performance (BEP) simulation model require significant effort for set up, limiting the potential utilization of modelling both in the design and operational phases. A methodology for semi-automated BEP simulation model creation could make this process much more expedient and as such lower to threshold for the use of such models. Building Information Models (BIM) are an information-rich repository that could be used to streamline and expedite the collection of such information. Concerning the building geometry, the Industry Foundation Classes (IFC) can provide static building information that include geometric configuration and material properties, but in a form that might not be directly usable for the generation of thermal simulation models due to the absence of 2nd-level boundary information. In this paper , a three-step methodology for (semi-) automated generation of thermal simulation models is presented, including: a query on the building data model requesting geometry-related information; a processing of the acquired data by a 2nd-level boundary identification algorithm, the Common Boundary Intersection Projection (CBIP) algorithm; and a transformation stage that converts the geometry information of IFC, along with the data obtained from the CBIP algorithm, to an Energy Plus and/or TRNSYS input file, with the latter being the main topic of this paper.