The acoustic classification of housing units is the end point of an articulated and complex process, which necessarily requires sharing experience and expertise both during design and realization. In recent years, many European countries and in particularly Italy, have seen a significant increase in the construction of residential buildings. Many buildings were built very quickly, often at the expense of quality, although maintaining their market value. As a consequence, failure to achieve the noise requirements is often the subject of lawsuits. The aim of the Italian voluntary Standard regarding the acoustic classification of dwellings is to provide a key to understanding the building quality in a easy and immediate way for the users and, at the same time, to develop a system that encourages continuous improvement of building’s production. In this work an overview of field measurements and classifications of new and refurbished buildings is reported. This was performed independently by different researchers in Italian Universities and Research Institutes. The results are compared with mandatory limits currently in force, taking into account measurement uncertainty and representativeness of building construction techniques, and suggest different interpretations for correlation between values of classification and perceived quality.