Ist die Hinterlüftung von Holzfassaden ein Muss?

Is ventilation of timber façades essential?

Following a major Swiss research initiative, "Fire protection in Timber Structures", exterior timber wall claddings incorporating specific fire protection measures have been permitted up to the high-rise limit of 22 m since 2005. This includes exterior wall claddings with a ventilation space that is interrupted and closed off from above at each storey level. Such façades have advantages when it comes to fire protection as they reduce or prevent the spread of fire behind the cladding. This has raised the question of whether the ventilation of timber façades is necessary at all from a building physics perspective. This matter was investigated as part of an Architecture, Timber and Construction research project at Bern University of Applied Sciences.