In 2023, a complex rehabilitation measure was carried out on several columns of an existing building in Chemnitz. The columns exhibited chloride-induced damage, which posed a long-term risk to the load-bearing capacity and safety of the structure. The aim was to sustainably repair the damage and strengthen the columns for future use – without altering the existing architectural appearance. The rehabilitation involved a combination of concrete repair and an additional layer of CRC. Within the repair mortar layer, one layer of carbon reinforcement grid approved within the CARBOrefit® system was embedded to increase durability and to control crack widths. This targeted measure restored the load-bearing capacity and significantly extended the service life of the structure. The execution on the corner columns proved particularly challenging, as these were equipped with a customised form of CARBOrefit® Type 3 reinforcement. This solution enabled a slender and precise strengthening that remains visually unobtrusive while meeting modern technical standards.