Soundproofing - weakest link? (Windows?)

49 dB the glazing. Depending on the size of the element, that is the ratio of frame to pane, the value of the entire element decreases by another 1-2 dB. It doesn't help if you don't also upgrade the roller shutter box with sound insulation. Each window has become on average 230 EUR more expensive as a result. Over 30+ years, I don't think it's unaffordable.

which window manufacturer if I may ask

It's all pointless if you don't also upgrade the roller shutter box with appropriate sound insulation ...

Are you still chilling (what a word) in your surely emerging garden ...? Rhineland greetings

The profile is from Kömmerling, 88 mm installation depth.

Construction expert, I don't quite understand the question...

OK Kömmerling profile - thanks Ordered locally from a window manufacturer or online / abroad?

A local window manufacturer produces windows using the profiles. Whether this is also available over the internet.. certainly. There are also profiles with even greater installation depths, for example from Veka there are 90 mm. But the decisive factor is the glazing.