Is a roof window really not feasible with a roof pitch of about 12°?

Is that so? I would first check whether their installation guidelines allow for a window surface. Because I do not read at all that they have no problem with it. Rather, they remain completely vague. In my opinion, the statement is so wishy-washy, it will immediately melt in your hands and slip through your fingers in case of doubt [emoji6]

If the installation guidelines explicitly allow for the framing of roof windows, you only need to find a window builder AND roofer to install it - and now comes the important part - assume the warranty. And this could get tricky. The roofer is still dealing with the system outside the ART (recognized rules of technology), i.e. in case of problems, he is already on the hook. If something becomes leaky, it starts. The window builder says he did everything right, refers to the roofer, who says he did everything right, refers back to the window builder. You are left out in the rain then - not only figuratively. I would check whether the window is so important there that it is worth the risk of weakening the roof sealing and having shit later. Alternatively, if the development plan and budget allow, look for another roof covering (e.g. standing seam) that may integrate roof windows significantly better. I would not do it on the roof construction with BRAAS 7+, throw out the window and use the money for something else. However, I do not know where (or for what) the window is needed.

I rather have the impression that the architect's concerns do not lie in the fact that the roof window breaks through the roof surface, but in the area of application of the roof window itself: 7° slope is untypically low for roof windows and untypically high for flat roof light domes. For the choice of the right window, this slope is neither fish nor fowl.

The 7 degrees are with us, I believe it was 12 degrees at the TE. But that probably does not invalidate your statement, does it? [emoji4]

Light domes typically go from 0-15 degrees. That should not be an issue.

Exactly, says Velux as well. We have 12 degrees.

Skylights typically go from 0 to 15 degrees.

Exactly, Velux says so too.

If the manufacturer (and its warranty conditions) say so, the architect should not disagree. Whoever pays, orders – so, they give the instructions.

I think it was 12 degrees in the OP’s case. But that probably doesn’t invalidate your statement, does it?

That’s right. What this specifically means here: if you want to replace it later, there might not be a manufacturer willing to go along with this slope. I don’t see more risk if the currently planned manufacturer agrees.