## Acoustic highlights in nordic building tradition.

Anders Ågren,

Division of Sound & Vibration, Luleå University of technology

The paper shows a selection of common light weight structures that are predominant today in the Nordic countries. Construction drawings are shown as well as measurement results from labs and in situ. Special focus is addressed towards modern Swedish constructions which will be included in the new Swedish national research programme for sound insulation in light weight houses. The ways to construct that are most predominant today can be categorised in mainly five types: timber in combination with boards, steel beams in combination with boards, thin board beams in combination with boards, more massive plywood board beams in combination with relatively massive plywood boards, integrated massive timber T-beams integrated with massive cross laminated plates. Production concepts vary from a delivery of flat elements to delivery of almost key-ready apartment volumes. The acoustic key question is not to produce breaking sound insulation at any cost, but to deliver cost-efficient solutions that can be designed for the sound insulation class that is ordered and paid for. Some solutions how this is dealt with are presented where examples for flanking transmission, suspended ceiling problems and floor stiffness solutions are shown.