LOD2 for energy simulation (LOD2ES) for CityGML: A novel level of details model for IFC-based building features extraction and energy simulation

As a widely accepted urban geographical analysis data format, CityGML proposed different levels of details (LOD) for buildings, and LOD2 is the most recognized level for various energy analyses. However, building energy simulation requires detailed information on the geometry and thermal properties, LOD2 is not sufficient for large-scale simulation of urban buildings. This study proposed a novel LOD2 for energy simulation (LOD2ES) that extends LOD2 with additional information on façade, glazing, internal geometry, and roof details. LOD2ES can extract relevant abstracts from standard Industry Foundation Classes files and construct efficient energy simulation and assessment models. To validate the proposed LOD2ES data scheme, this study conducted a case study on 10 typical buildings and compared LOD2ES with other mature data schemes, including LOD2, LOD2.5, and LOD2plus, in three different climate regions. The results show that with improved building information, the simulation results have a significant variation (20%–22%) from conventional LOD2 models. It has a better performance than LOD2plus and the running time is about 15% less.