Comparative analysis of thermal and acoustic performance of building elements Antonino Di Bella Department of Industrial Engineering - University of Padova, Padova, Italy. Nicola Granzotto Department of Industrial Engineering - University of Padova, Padova, Italy. Cora Pavarin Department of Industrial Engineering - University of Padova, Padova, Italy. Summary The acoustic and thermal insulation performances play a key role in the characteristics of energy saving and comfortable living in modern buildings. However, high thermal and acoustic performances are difficult to obtain at the same time in building structures because of the different physics phenomena related to these two aspects of energy propagation in materials. In this work experimental measurements of sound reduction index, carried out according to ISO 10140 series standards in the Acoustics Laboratory of the Department of Industrial Engineering of the University of Padova (Italy), are analyzed for nearly 100 vertical building elements in basic configuration and with linings for improved thermal and acoustic performance. The sound reduction index and the sound reduction improvement index for different types and combinations of lined walls were measured and then thermal transmittance was calculated for each structure. Possible correlations between thermal and acoustic performance have been evaluated taking into account the different types of materials used. PACS no. 43.55.Ti 1. Introduction 1 Energy consumption of buildings depends significantly on the criteria used for the indoor environment and building design and operation. Therefore, thermal insulation of building structures is a topic of fundamental importance in building design. Often the overall quality of a building is mainly estimated on the basis of energy consumption, which overshadows other aspects that are particularly relevant for the living comfort, like the sound insulation. The problem is particularly relevant in the energy retrofit of existing buildings or adaptation to more restrictive building codes regarding energy savings. In fact, in these cases the thermal insulation obtainable from the building envelope or the internal partitions between different housing units becomes the major reference point for the choice of materials that compose the building elements. 1 (c) European Acoustics Association Very often the effect of an increase in the thermal insulation of building elements is associated, directly or indirectly, to other benefits for users (environmental and economic benefits, customer satisfaction, building structural integrity, fire protection and, at least, reduced noise levels) [1]. However, some of these claims are not based on experimental evidence or on a realistic study of the cost/benefit ratio in terms of acoustic performance. It’s still a very widespread common place that the increase of the layers in a building element is also beneficial for the sound insulating capacity, without regard to the combination of certain key elements, such as density, thickness, porosity, and stiffness of the proposed materials. The aim of this study is to investigate the relationship between the reduction of the thermal transmittance and the increase of soundproofing capacity of a building element when different types of insulating materials are applied.