CK Structural Engineering Consultants was fully responsible for the structural design part of the project across the entire range of required tasks — from the stage of structural survey and on-site and laboratory tests to the complete design of strengthening interventions. The building, originally constructed in the 1930s, consists of load-bearing stone masonry system, with later additions made using a mixed system of reinforced concrete and brick masonry. The structural works were carried out within the framework of a comprehensive refurbishment of the building, which included a wide range of architectural modifications and extensions (such as the creation of new openings, the addition of staircases, green balconies, and an extension of part of the structure, among others). The on-site and laboratory tests included the structural mapping and verification of the building’s structural system, as well as the determination of the mechanical properties of individual materials (stone and mortar). The XRD (X-Ray Diffraction) method was also applied for the mineralogical identification of the materials. The structural analysis was performed using ETABS software by CSI and FESPA software by LH Logismiki. Due to the particularly extensive nature of the structural modifications, the strengthening measures mainly consisted of a combination of new reinforced concrete members and the application of shotcrete jackets, and to a lesser extent, the localized use of steel plate reinforcements (FRP).