## "Impact sound insulation descriptors in the Nordic building regulations - Overview special rules and benefits of changing descriptors"

Klas Hagberg and Birgit Rasmussen (klas.hagberg@afconsult.com; bir@sbi.dk)

Birgit Rasmussen, MSc, Senior Researcher
SBi, Danish Building Research Institute
Aalborg University
Dr. Neergaards Vej 15, DK-2970 Hørsholm
Direct: (+45) 9940 2364
Mobile: (+45) 2165 0873

All Nordic countries have sound insulation requirements specified in the building regulations or in sound classification schemes, Class C, referred to in the regulations and published as national standards, which all originate from a common Nordic INSTA-B proposal from the 90’s, thus having a lot of similarities. However, the descriptors and other rules differ more than what is obvious at the first glance. The present use of different descriptors and additional rules is partly a heritage from the past and partly caused by later national revisions without cooperation with the other Nordic countries. These national rules are not easy to find, unless all details of standards and other documents are known and studied carefully, and they cause problems since the building industry is not national anymore. This paper gives an overview of special national rules in the Nordic countries regarding impact sound insulation requirements and is related to an equivalent paper about airborne sound insulation requirements. The papers also describe the major benefits of reducing the number of special rules and of changing descriptors to those which best support protection of the residents and development of the building industry, both aspects in consideration of the European perspective and cooperation in COST Action TU0901.