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Calculation of the uncertainty of the sound insulation prediction according to EN 12354-1

Working Group 1.72

This Excel sheet calculates the uncertainty of the resulting sound reduction index R'w in accordance with DIN EN 12354-1:2000-12 [1], especially for solid buildings.
The uncertainty u-prog corresponds to the total uncertainty of the prognosis, consisting of the error propagation of the input values as well as an uncertainty of the transfer of the value calculated to the real building situation. These uncertainties usually come to 0.8 dB [2]. The uncertainty value stated corresponds to the so-called "simple uncertainty" or a standard deviation, i.e. under the assumption of the normally distributed scattering, approx. 84% of the actually attained sound reduction values are above R'w - u-prog.

The sound reduction indices of all the building elements involved, the airborne sound improvement values of all the acoustical linings which might exist including suspended ceilings and floating floors as well as the vibration reduction indices around the partition are to be entered. The unit is in each case the dB. In addition, the height and width of the partition are to be indicated in metres. To make the input easier, the input fields in the Excel table and each associated spatial area in the sketch are marked in corresponding colours. The sound reduction values and the vibration reduction indices can be taken from [1] or if necessary from the test certificates if available. The values of the previous "safety margin" in accordance with DIN 4109 can be implemented approximately for the uncertainties when defined values are missing. Considerably higher values can, however, be appropriate in particular at the junctions around the separating  element.

This Excel sheet was developed and tested very carefully, among other things, with the calculation example in DIN EN 12354-1. Errors may have crept in despite this. Please take note of the disclaimer on the spreadsheet for this reason. If you have any comments or questions or if you discover any errors, we would be pleased to hear from you at volker.wittstock(at)ptb.de.

You can use the Excel sheet online or download it and use it on your computer by clicking the right mouse button and selecting the option "Save Target As".

The creation of this spreadsheet was supported financially by the Deutsche Institut für Bautechnik (DIBt).

[1]  DIN EN 12354-1:2000-12
Bauakustik - Berechnung der akustischen Eigenschaften von Gebäuden aus den Bauteileigenschaften - Teil 1: Luftschalldämmung zwischen Räumen; German version EN 12354-1:2000

[2]  Volker Wittstock: Erarbeitung brauchbarer Schalldämm-Definitionen für die neue DIN 4109. Final report on the research project of the same title, currently being printed


Physikalisch-Technische Bundesanstalt
Arbeitsgruppe 1.72, Angewandte Akustik
Bundesallee 100
38116 Braunschweig