Replace/extend front door filling due to sound insulation

So the front door has a surface panel on the outside, so unfortunately that is out of the question. Although inside there are only classic plastic glazing beads adapted, which are also present in windows. You can remove those and then I'll see how it looks there. The carpenter is (as mentioned) happy to create a kind of surface panel on the inside as well.

I also had the idea of the bitumen heavy-duty foil. On top of that a Knauf Silentboard and then let the carpenter work on it?

Is the filling covering the wings on the outside, or why are you thinking more about doubling up than about replacing the filling?

I assume that replacing the filling in a plastic door supported by only three hinges is only possible within certain limits. Ultimately, more weight is needed to absorb the sound. Currently, only thin plastic and a PUR filling seem to oppose that. Still, I would ask the supplier what they can do. That will be the cleanest option. I wouldn’t consider just stuffing something in and filling it. I also wouldn’t noticeably increase the weight of the door without consulting first.

We will definitely inquire with the dealer; you're right. Nevertheless, I think that heavy plastic foil and a bit of plasterboard shouldn't significantly affect the hinges. It's not about blocking the sound of a highway, but just dampening the noise of cars in the hallway, at least decoupling it a little. :)

The note about the weight is definitely justified and important! Thanks for that. :-) If in the end the door is soundproof but falls out of the anchor, you haven't gained anything.

A nice heavy curtain absorbs quite a bit of sound ... :D

(but do you really want to have that in the entrance area?)