The article presents the challenges faced during the renovation works completed in 2024 on the building of the former Zamość Academy in Zamość. It focuses not only on the work conducted on this specific historic monument but also on the unexpected findings and discoveries made during the construction and renovation process. Among these discoveries were 18th-century illusionistic wall paintings in the chapel and the Jan Kanty Hall, floors from various periods, the foundations of older buildings on which the walls of the current academy were erected, as well as 18th-century recessed latrines preserved with wooden seating elements and risers. The article also discusses how, in the 19th century, attempts were made to deal with the effects of high wall moisture and the heating system used in the earliest periods of the building's history. Additionally, it explores the circumstances of the discoveries, their impact on the construction process, their significance for the history of the building, the city, and the region, and how the renovation work, which exceeded the scope of the original construction project, influenced the overall renovation process.