The design of retrofitting strategies for historical buildings involves various challenges. The aim is often not only to save energy while providing acceptable indoor conditions for its users, but also to preserve the building and potential cultural artifacts, making it a multi-criteria issue, with multiple demands on the simulation tools and methods. This paper describes one way to fulfill on these demands through a serial, stepwise simulation process and a special tool, designed for that process. A case study, performed with the use of the method and tool, is presented. The results show that the method is workable and provides good agreement between simulated results and measured data.