Humidity in buildings is a common problem, and condensation is one of the ways this phenomenon occurs. This article analyzes three real case studies with different condensation contexts: on floors, on gypsum ceilings, and in air-conditioning ducts. The methodology involved technical inspections, thermal measurements, and the application of practical solutions such as enhanced thermal insulation. The results demonstrate that design and execution flaws are recurring causes and that the combination of early diagnosis and appropriate technical specifications is fundamental to preventing the effects of condensation. It is concluded that to minimize the negative impacts of condensation, careful planning is crucial from the project conception phase until the end of the building’s service life, involving qualified professionals and the use of appropriate materials.