Managing uncertainty in building acoustics : comparisons of predictions with the 12354 standards to measurements

Abstract: The thesis summarizes results of research on the uncertainty of standardized methods applied in the field of building acoustics, with respect to calculations as well as to measurements. Eight published papers are appended to the thesis. It also gives references to relevant research that has been published in this field of interest, to give the reader a wider outlook. The EN 12354 series of standards on calculation methods, published in 2000-2009, have facilitated the management of building acoustics issues during the building process. To allow for lean designs of building structures, the uncertainty of the calculation methods (compared to measurement results) must be known, as the measurement results in finalized buildings are typically used to prove fulfillment of formal requirements. The standards facilitate a structured comparison of calculations (made during the design work) to the results of measurements. These comparisons have been used to estimate the combined uncertainty of the standardized methods and to derive safety margins to be observed during design work (i.e. to be added to calculated values). The combined uncertainty is estimated from the differences between field measurements of the performance of buildings (made according to international standards) and the corresponding theoretical estimations of each case (according to standardized calculation methods). There are several factors that complicate such comparisons, e.g. uncertainty of the input data of building elements, applicability of the calculation methods to the real building construction, effect of poor workmanship and uncertainty of the field measurement methods. Some studies address the uncertainty of the field measurement methods specifically. A separate section discusses management issues, which serve to reduce uncertainties pertaining to unclear definitions of requirements, poor building construction documentation and responsibility to be taken during each phase of the building process.