BIM to GIS-based building model conversion in support of urban energy simulation

Sammanfattning: In the context of growing population and increasing greenhouse gas emissions, urban energy planning is becoming a topic of high concern. With the rapid pace of urban construction, it is claimed that 40% of America’s total energy consumption is accounted by the building sector. Energy modelling and simulation are believed to be effective in supporting urban energy planning. Today, the growing availability of 3D city models has facilitated energy simulations at various scales. While Building Information Model (BIM) provides users with the possibility to explore the energy consumption alternatives of a single building, GIS-based city-wide building models offer the chance to simulate urban energy demand at the city scale. Considering that most of the existing GIS-based building energy simulations are using models with a lower Level of Detail (LoD), the aim of this study is to extract geometrically detailed and semantically correct information from BIM models to construct GIS models with a higher LoD in order to support more accurate Building energy simulations. Semantics of BIM models from different sources are matched with that of GIS-based building models, and geometry of BIM models are converted to conform to GIS-based building model standards. Specific concern is given to the extraction of openings that are absent from lower LoD CityGML. After conversion, the result is used to perform a simple energy assessment to see how much influence a higher LoD CityGML model has on the energy simulation of a building.