The architect said that instead of a 90x120 window, a 120x90 window could also be installed. Could that be?
If the regulation is not more specific about it, then formally, probably yes. However, I would not forget the purpose of such an emergency escape route: so just imagine, the firefighter saving you in full gear including breathing apparatus would simply turn 90°
The city says it does not matter whether 90x120 or 120x90. I am allowed to build both as an escape route without any problems. The firefighter actually has to be rotated 90° to enter. Of course, with a maximum distance of 1 m from the basket to the window.
In the MBO no orientation is specified for the 120x90cm. What is important in this regard is that the 120x90cm are clear opening dimensions of the window and not the rough construction dimension. The escape route window can even have a central mullion, but I currently do not know the minimum dimension for that.
No, somewhere I actually read that it might be possible to subdivide again. With a fixed center post. No idea if that’s true, I don’t intend to do that either. The post can be opened with a wing.