Plastic, 86mm profile from Rehau with 0.6 glazing.
Thanks; I thought so. It shouldn't actually occur with aluminum because their value is lower.
There’s not much you can do about it - except use the roller shutters. But you should be glad that - even if the fitting is annoying - it also represents a visible quality feature for very good, thermally insulated windows.
Whether it’s Rehau or another frame manufacturer doesn’t matter; they all come from at most, in my opinion, 3 manufacturers anyway.
Rhenish greetings