A number of current research projects aim at increasing energy efficiency in production by using com-prehensive simulation models of manufacturing plants. In order to gain knowledge about the energetic optimiza-tion potential of machine tools, a simulation model of a turning lathe is developed. Using an object-oriented modelling approach allows combining mechanical, electrical as well as thermal aspects in a structural manner into one comprehensive multi-domain model. This bottom-up approach is combined with stepwise top-down model refinement in three stages in order to identify numerical boundaries of the simulation. Simulation re-sults are validated against measurement data. Though object-oriented modelling leads to flexible and modular models, the translated equations are less efficient during simulation, therefore making it necessary to perform manual adjustments in the model. To increase simula-tion speed, multirate simulation is performed in Sim-scape using local implicit fixed-step solvers.