This paper presents an excerpt of the acoustic retrofit of Cinecittà Studios. It focuses on the ante and post operam conditions concerning the improvement of internal comfort and façade sound insulation of “Teatro 10”. Achieving optimal acoustic conditions, considering the specific building's use and the client's requirements, highlighted several issues. The main goal was to make the "Teatro 10” available in a short time frame with low-noise construction activities, that would not interfere with the adjacent theaters’ activities. The investigated solutions had to be both effective and sustainable, in order to make the theater acoustic characteristics suitable for the specific intended uses. The paper presents a comparison between the results of the ante and post operam measurement campaigns, with particular reference to the chosen design solution.