An urban energy system model processing GIS data, which is called EnerGIS, has been developed at the IPESE group. In order to both reuse this model for further applications and to develop new concepts, the focus of this project lies on the refinement of the modelling of the hot water production system in EnerGIS. This is due to the fact that the energy consumption for domestic hot water (DHW) has so far been just sketchily defined. For this purpose, the modelling of the hot water production system will be reviewed and will be compared to other existing modeling methods in order to find potentials for improvements.