The present paper describes a semi-automatic process, in which a typical CityGML 3D building model is enriched with explicit thermal energy related information and stored in a CityGML Application Domain Extension (ADE). Special emphasis is given to the discussion of suitability of existing CityGML models for city-wide energy simulations. Possible conflicts between the requirements of urban energy simulation systems, the capabilities of the CityGML Energy ADE and the available data are presented, which can be partly resolved by specific geometric / semantic corrections of the model data. For testing and evaluating the approach, interfaces for two building energy simulation systems have been developed
