Flooding events pose a high risk to valuable monumental buildings and their interiors. Due to higher river discharges and sea level rise, flooding events may occur more often in future. Hygrothermal building simulation models can be applied to investigate the impact of a flooding event on the environmental conditions inside a building. The objective of this study is to develop such a model that is able to evaluate the best fitting drying regime for historic buildings. A model is created based on on-site measurements of the indoor climate conditions in one building that had to cope with flooding in the recent past. The result of this study is a hygrothermal building simulation model that can predict the indoor climate conditions inside a room as a result of a flooding event. Different climate control systems can be integrated in this model to evaluate the most suitable drying regime to minimise the risk to the building, its interior and its collection. Furthermore, damage functions can be applied to analyse the risk to the collection caused by the flooding event.