Our company’s services include the assessment of the structural bearing capacity of a seven-storey reinforced concrete private clinic building with basement and roof floor, built in the period 1965-1970, as well as the design of the strengthening required for the structural elements based on the results of the assessment study. In the context of this study, mapping and on-site investigation of the structural elements were carried out, as well as documentation of the existing materials according to the Greek Intervention Regulation (ΚΑΝ.ΕΠΕ.). Regarding members retrofitting, the shotcrete jacket method for the columns and the use of carbon fiber reinforced polymer (CFRP) plates for the strengthening of beams were considered more suitable for application. Moreover, the structural design of both a new intercommunication staircase and a lift-core system was conducted, following the new architectural design study of the building. All design analyses, i.e. the structural assessment study and retrofitting design study, were carried out using the Fespa 20 v.8.1.0.22 software package.