Opsis completed the architectural restoration study for the listed as a monument school building on Kriezotou Street on behalf of the Municipality of Thessaloniki. The site carries a long and layered history: the plot was first purchased in 1928 by the Mission Laïque Français. Traces of the organization’s original inscription remain visible above the main entrance. The building was constructed between 1936 and 1939, based on designs by A. Paul Leclerc, to house the females’ School of the Mission Laïque Française. In 1959, it was acquired by the “Thessaloniki School Building Construction Fund” to accommodate the 5th Boys’ Gymnasium of Thessaloniki.
In 1987, the building was officially designated a work of art, as it represents a distinguished example of International Style architecture. As a characteristic school building of the 1930s, it also belongs typologically and morphologically to the monumental architectural language commonly found in French public buildings of that era.
The study focused on restoring the building’s historic form following the necessary structural interventions to its load‑bearing system, while also adapting it to contemporary standards for educational facilities.
The restoration of the building envelope aimed to highlight and preserve its historical identity. Particular care was taken to ensure that structural reinforcement works would not alter the volumetry or architectural expression of the façades. Inside the building, however, the new structural elements—jackets, shear walls—remain visible and intentionally distinct from the original fabric. Every authentic element that could be reused was conserved and reinstated, while any new component was constructed, as far as possible, following the original design and using the same materials. Subtle variations in color, texture, or simplified ornamentation distinguish the new additions from the historic ones.