Roof window options

I would never install solar in a new building - and with Elektro-DF you can only open the window a little bit - it's enough for ventilation, but then the unit doesn't stand out much. It's probably not a big deal in your situation, but I wanted to mention it.

Hello everyone,

we have a bathroom on the upper floor with approximately 8 m² floor space. Actually, we wanted to install two roof windows with the dimensions 78*114 (W*H), as agreed with both the planner and the carpenter.
Now the roofer says that due to the battens, the 114 cm dimensions and also the 98 cm dimensions do not work, but only 55 * 78 cm (don't ask me what went wrong there - I assume the detailed planning could have been more extensive here -.-). Well, now it's like that.

Hello,
as a layperson, I would assume that with appropriate reinforcements it should also be possible to install your originally planned windows.
If this was also discussed beforehand, the costs of any necessary reinforcements would not be your problem, but rather the carpenter's. (Warning: layperson's opinion!)
I would therefore try to have a direct conversation with your carpenter again (possibly also together with the planner). You had some idea behind the planning, so I wouldn’t be satisfied with a simple "does not work."

Purlin or rafter roof?

Rafters... but also purlins - at least foot and middle purlins. However, the roofer said it probably also has something to do with the batten spacing and the tile size. Geometrically, the whole thing is of course also limited by the ceiling joist and the foot purlin.

You also have rafters with a purlin roof - just so you don’t mix that up now ;).

For me, a rafter is simply removed if it gets in the way because of a roof window - that’s just how it works with a purlin roof ;).