Flanking transmission from structure-borne sound sources in heavyweight buildings over multiple junctions

In many buildings, rooms that contain vibrationally-active machinery are not always adjacent to habitable rooms; hence it is useful to be able to predict vibration transmission over multiple junctions to non-adjacent rooms. In the first version of the European Standard EN 12354 Part 5 (2009) the equivalent vibration reduction index was introduced to account for transmission across multiple junctions. This was removed in the 2023 version but there remains a need for these estimates at the design stage of a building. This paper compares predictions of vibration transmission from a wall to different receiving rooms in a large heavyweight building. The SEA matrix solution is compared with SEA path analysis using different numbers of paths to assess whether path analysis is feasible, and if so, what errors can be expected when using a limited number of paths. An alternative approach to path analysis is to use transmission functions for heavyweight buildings, and an initial assessment is made to see whether these are expected to vary significantly depending on the position in the building.