Use of the ISO 12354 standard for the prediction of the sound insulation of timber buildings: Application to three case studies

The ISO 12354 standards provide a method for modelling the sound insulation of building elements using the performance of the single elements as a starting point. The revision of the ISO 12354 Part 1 and 2 standard makes it possible to model timber buildings. In particular, the standards provide prediction formulas for estimating the vibration reduction index (Kij) of heavy and light weight junctions and CLT junctions. The aim of this research is to study the dependence of the ISO 12354 output values on the input data fed to the model, in the specific case of timber buildings. The prediction tools were applied to three different timber buildings on which sound insulation and flanking transmission measurements were carried out on site. Different input data were used: laboratory and in situ measured values of airborne sound insulation, impact sound insulation and flanking transmission. The calculated values are compared with in situ acoustic tests of airborne sound insulation and impact sound insulation. The results show that the blind application of the ISO 12354 model can provide results that differ significantly from the measured on-site values; considerations are drawn concerning the availability of input data and the resonant transmission.