Predictive methods for the estimation of acoustic performance in buildings are largely used at building design stage. The sound insulation capacity of numerous constructive systems are well known through a process of analysis that starts from laboratory measurements of sound insulation and flanking transmission of airborne and impact sound of building elements, in order to obtain input data for predictive methods, and ends with field measurements for the validation of the estimation process and, possibly, for the compliance with the building requirements. Nowadays, Cross-Laminated Timber technology is fast becoming the preferred constructive system for many buildings, thanks to its flexibility and speed of build along with its ability to achieve a greater number of storeys than traditional timber frame. On the other hand, for this construction technology the input data for the prediction methods are often not available and extensive research on the validation of numerical methods for the estimation of acoustic performances have not yet been carried out due to the relatively small market share of CLT in building industry. During independent research, carried out recently by the Universities of Cagliari, Bologna and Padova, it was possible to apply a complete process of evaluation, prediction and estimation of the acoustic performances of timber buildings made with CLT structures. A large set of data from laboratory measurements of CLT building elements carried out in accordance with standards of ISO 10140 and ISO 10848 series was applied to the recently revised ISO 12354 prediction method for the acoustic design of several residential buildings. Then, field measurement were carried out according to standards of ISO 16283 series to estimate the accuracy of the prediction and, in some cases, the influence of laying techniques and workmanship on expected results.