ᐅ Block up windows only from the inside

Hello everyone,
I have two plastic windows in my bathroom, and I would like to block up one of them to install a shower.
The bathroom is located on the first floor (1st floor) of our house.
However, I want to keep the window visible on the exterior facade (east side facing the neighbor).
My idea:
Seal the window with silicone, apply a mirror film to the glass, stick a piece of roofing membrane onto the frame, then fill the rest with insulation wool. Cover it with a second membrane and finally clad it with moisture-resistant drywall.
My question is whether this will really protect against moisture and be sufficient, or could it possibly damage the window?

Hello,

You want to leave the window installed and then seal it from the inside, right?
First of all, I have to ask: WHY?
Secondly, from a construction and building physics perspective, this is nonsense and incorrect. This area will rot completely sooner or later (I suspect sooner).

So my advice is to fully close off the window and follow the construction of the rest of the wall... then nothing can go wrong.

Regards

Thank you, Curb, for your honest reply. The idea was actually to save work since the window is on the first floor but can only be accessed from the garden side at the back of the house (height about 5m (16 feet)). Furthermore, I think that later you would be able to see the plaster and paint that were applied afterwards.
I guess I’ll have to bite the bullet... :-( .
Best regards, back

Take comfort in knowing that it will look better afterwards.

Hello,
I can only suggest that you completely remove the window, as otherwise mold will really start to develop, or over time moisture could penetrate through driving rain and damage the wall. Erect scaffolding outside yourself or have it installed, then plaster and paint. Of course, this will be visible.

Best regards