CityGML- based 3D city model for energy diagnostics and urban energy policy support

This paper aims to evaluate the accuracy and strength of a new approach that automatically calculates the heating demand of whole district areas, modelled in 3D with the open standard CityGML. For this purpose, two residential districts in Ludwigsburg and Karlsruhe have been chosen as case studies. To evaluate the accuracy of the model, the simulation results were compared to real measured consumption data and the model uncertainties were analysed. The mean deviations found between simulated and real district heating consumption are 7% and 21% for the two cases. Beside the thermal diagnostics of the existing building stock, the paper shows how 3D city models could play a central role in the development of urban strategies for renewable energy supply and energy efficiency measures on both district and city levels.