There are nearly 3,000 windows on the four faces of the 28 story central tower of the Indianapolis / Marion County, City/County Building. This building was built in 1962 and the exterior envelope is a structural curtain wall. The investigation of the curtain wall and window assemblies revealed greater problems on the building’s north face and over-all, more problems on upper floors than lower. The single glazed windows were losing integrity; water proofing materials were failing with resultant problems that had an impact on the entire structure. Thermal efficiency was less of an issue as the building systems and occupancy generates significant heat that needed to be dissipated through one means or another. Due to the large number of windows in the high rise, alternatives to complete window replacement were studied. The resultant solution combined several approaches. First, the most critically compromised windows were replaced and secondly, windows that could be effectively repaired (primarily through wet glazing) were so reconditioned in place. The project, including 56,000 sf of roof replacement.