Almost every window has scratches - what is considered normal?

So there are different datasheets: "KU.01: Visual assessment of surfaces of plastic windows and door elements" "Guideline for the assessment of the visual quality of insulated glass" And according to them, you have to accept some things. Some defects only count if you see them from a certain distance, etc.

so there are different information sheets:
"KU.01: Visual assessment of surfaces of plastic windows and door elements"

"Guideline for the assessment of the visual quality of insulated glass"

And according to them, you have to accept some things. Some defects only count if you see them from a certain distance, etc.

Excuse me? That stuff is issued by the association "Fenster + Fassade" – for me, that is just wishful thinking by the manufacturers. I also can’t just write an info sheet for the IT sector that says "System crashes are to be accepted without exception, except within a 30-minute interval. Monitor flickering is normal."

Apparently, our installation crew handled the windows very roughly. There are scratches and damages to the plastic on many edges; the removal of the protective foil was apparently started with a screwdriver in some places, causing small notches.

End caps of the profiles are broken (you obviously cannot see that from 5 meters away in diffuse light – as the info sheet would like – of course not...) and on two windows the area below where the panes sit was drilled sloppy, supposedly to attach a transport hook. But how is thermal insulation supposed to work if the air gap is not sealed there?

Does that look like a defect to you?

More pictures

The question is 1. whether there are objectively defects and 2. how you can enforce your rights.

I dare to claim: Your contracting party will not voluntarily tear out all that stuff, dispose of it and have it reinstalled by a quality company. Keep us updated!

The "Guideline for the Assessment of the Visual Quality of Glass for Building Construction," developed by the Technical Advisory Board at the Institute of Glazier Trades for Glazing Technology and Window Construction, Hadamar, and by the Technical Committee of the Bundesverband Flachglas e.V., Troisdorf, I also had to familiarize myself with. After an initial "Outside the field of vision, you don’t see it, no defect," glass was eventually replaced in our case. I don’t know if this helps you, since your problem is mainly with the frames...

The question is 1. whether there are objectively defects and 2. how you can assert your rights.

Regarding 1.
That is certainly the crux of the matter. If I were to transfer this kind of defects to any other object (cell phone, car, computer, sunglasses, picture frame, speakers, whatever), the answer would be clear: this is not a product in new condition.

Polishing out scratches (which was one of the suggestions) is problematic in that there is not an infinite amount of material available. If I already have less material from the start, I no longer have the possibility to polish it in the future because material has already been removed.
This is also true for car paint: it cannot be refinished endlessly.
The plastic windows are practically meant to last forever – the appearance one would like to be able to refinish in a few decades.

Regarding 2.
Well, there are plenty of options. The most reasonable would be an open handling of the matter by the developer. For me personally, there are areas on the window that do not necessarily have to be replaced (damages on the bottom edges, for example), but at least should be compensated in another way. Other things, such as the big dent and the warped door as well as the windows with incorrect drillings and obvious scratches, definitely do.

I dare to claim: Your contractual partner will not voluntarily tear out all that stuff, dispose of it, and have it reinstalled by a quality company. Keep us updated!

I will do that! My contractual partner is a developer who outsources all things to third parties. In this respect, they have a significantly longer lever against their contractors, since unlike me they do not just award one contract in their lifetime...

Please what? The stuff is published by the association "Fenster + Fassade" – to me, this is initially just wishful thinking from the manufacturers. I can't just write a datasheet for the IT sector saying "System crashes must be accepted without exception except at intervals of 30 minutes. Monitor flickering is normal."

Unfortunately, I don't know whether and how the datasheets are binding or contestable. That would certainly be interesting. So far, I also haven't had an appointment with the window manufacturer to discuss the errors. To address the IT area you mentioned: For TFT displays, a certain number of (sub)pixel defects are also allowed, and there is no right of return. But here, there is even ISO 9241-307 with different classes.