The former public library originally based in the Wilhelmspalais (built in 1840) was converted into a town museum. The architectural plan required a complete gutting of the listed building located in Stuttgart city centre. The demolition was subject to strict vibration monitoring. The vertical load transfer is entirely detached from the historic stonework façade and will be transferred solely through the new internal building structure. The stair and lift cores provide the vertical bracing required to resist earthquake loads. The façade “rests” against the new building while only transferring horizontal loads to it. The pre-stressed flat concrete slabs were thermally activated by integrating water pipes into the concrete. In areas of large spans the slabs were pre-stressed. Suspended ceilings could be avoided by integrating the ventilation ducts within the flat slabs. This allowed for an optimisation of the ceiling heights and offered more flexibility within the restrictions imposed by the maximum eaves height of historic facades. The waterproofing of the building was constructed solely with water-resistant concrete. The design was implemented using a 3D building model in compliance with the BIM concept.