Owing to a high cost pressure and the need for a reduction of carbon dioxide emissions for manufacturing calcium silicate masonry units (CS), the CS-industry strives to cut the energy consumption. The most energy consuming process step is the autoclaving. About 87% of the energy is required for this particular process step, where the green bodies are steam-hardened at 200°C.For reducing the energy consumption, most of the alternatives aim at optimizing the complete manufacturing process. In this paper, the focus is put on an optimized loading process for the autoclaves, in consideration of preceding and subsequent process steps. For this purpose, a simulation model is developed, where different strategies of loading are implemented and tested. This model can be used to find optimally scheduled assignments of production orders to the available autoclaves, based on the volume of each manufactured product.The analysis of the tested strategies shows, that it is possible to save up to almost 9 % of the required energy for autoclaving by an optimized assignment of the available autoclaves.