Only belief allowed, solutions?

No idea.., But watch out with your contractor - the ceiling height of 2.46 RBM is not ideal either. It should be 2.50. Anything else is excessive frugality.

Sorry for jumping in, quick question :)

Our standard says 2.635 raw construction and 2.45 clear dimension, will the floor covering still reduce the clear dimension or is it more or less already taken into account?

will the floor still be deducted from the clear dimension or is it basically already +- considered?

I don't think so. The word "clear" refers to that. It means the final measured dimension. For floors, you calculate with +-1 cm covering?!

I mean whether I can see from the building application (i.e. the paper I submit to the building authority) whether it is a dormer, because we wanted a dormer.

The forms apparently vary by federal state, I don’t know them all, and I don’t know the paragraph numbers indicating the procedural paths by heart. Whether you can answer my counter-question is not so important either. Your gable dormer remains excluded, no matter where you put the checkmark or how you call it. A development plan is not only for limiting sealing and protecting neighbors, but also reflects the municipality’s design intentions regarding cultural landscape preservation in construction. In other development plans, this even happens with a limit to the Franconian vacuum cleaner knee wall, which you are spared here. I do not advise you to go for a dormer here: if your planner “misinterprets” a height specification, it could result in a reduction of your house’s height.

Why is that not a dormer? What would be a real dormer now? A gable dormer is a cross gable, isn’t it? And according to the development plan, that’s not allowed, which is why we apparently have to stick with the (in my opinion) dormer?

You cannot “stick” to the dormer because you haven’t planned any dormer at all. Rather, it would be up to you to switch from the gable dormer to a dormer, which would be basically technically possible, but would look highly unusual and would not be practical (if you wanted to window it on the eaves side as usual). However, one could still build one for headroom reasons for an unrelocated dressing room passage (which would make for an extremely expensive passage—I just did not want to withhold the information here that, in my opinion, this error could be made if it was really wanted). A dormer is usually constructed standing on a knee wall purlin—and here at least from the visual point of view the development plan only allows that—as knee walls typically do not have that. Now the development plan here does not care whether you want to belong to the knee wall or the knee wallless faction. What is not indifferent to it, however, is the setback of the dormer behind the eaves line—which traditionally results from resting on the knee wall purlin. Instead, it categorically excludes that the roof structure interrupts the eaves line. Where it says so as formulated in this case, I read that as a clear indication that exemption requests would be rejected. We can only speculate here, as we could at most refer to the justification for the development plan, but not to a transcript of the municipal council meetings on its enactment. My experience says: forget the wish to have a gable dormer approved here instead of a dormer (whether it would have a shed roof or a gable roof does not matter). What grows from a knee wallless roof instead of a knee wall is and remains a gable dormer in building planning law—no matter whether common parlance cares about the difference or mixes the terms freely. The development plan is based on building planning law and not on common parlance; discussions about it would be pure philosophy and would not lead to different results in substance.

If the 50 cm roof overhang is drawn, it should rather be approved. What does the development plan say about the design of the dormer?

The development plan says as above that the roof structures must not interrupt the eaves line and thus allows what I consider an unequivocally expressed intention, dormers but not gable dormers. Your proposal apparently rests on the mistaken assumption of equating the legal eaves with the physical gutter. However, the legal eaves mean the figurative idea that you would interrupt the roof overhang with a plumb cut executed vertically above the outer wall. The idea that simply hanging a two-tile-wide apron in front of a gable dormer could reclassify it as a dormer is unfortunately naive from the building authority’s point of view.

okay I am now completely confused. I spoke again with the architect, who says what he planned is a dormer, when I google dormer, it also makes sense to me. But what you write sounds so knowledgeable and I don't understand it.

It doesn't matter what that roof thing is called: with a 1.55m parapet height it doesn't work, and it's not nice either (sorry).

I spoke again with the architect, who says what he planned is a dormer; when I google dormer, that also makes sense to me.

Then you should actually have also googled the Wikipedia explanation, which states: "The gable end of the dormer is set back from the eaves of the main roof towards the ridge and has [U]no structural connection to the outer wall beneath." That the architect calls the cross-gable a "dormer" can happen. I had already pointed out the connection that a cross-gable with a knee wall functionally takes the place where a dormer would be inserted with a short wall. So cross-gable and knee wall belong together in a way just as dormer and short wall do. Now it is such that until about thirty years ago, the mixing of regional architectural styles was not as widespread as it is today. It can’t be clearly pinned down along a kind of "Weißwurstäquator" aka Main line or a primary dialect shift line, but there were areas whose building culture traditionally only knew the short wall or the knee wall. Due to migration movements of the “original peoples” between the short wall and knee wall regions, the terms have since become mistakenly synonymous, although they are fundamentally opposite ways to achieve essentially the same purpose. Those preserving the regional character of the building cultures among the city council members responsible for zoning plans dislike this miscellany, and they strive to counteract it. In particular, in Franconia it is preferred to keep the knee wall height mostly limited to about half a meter. Other communities – such as yours – leave the knee wall height open and then regulate through the non-penetration of the eaves line that the roof extension should be recognizable as an addition (or they see the non-penetration of the eaves line itself as the protected architectural heritage). Also, the number or total width of dormers (maximum half the house width, more often only a third) is often limited. In this respect, your zoning plan is therefore more than average liberal; likewise regarding the knee wall. Your problem actually only arises because you want to fully exploit both freedoms at the same time. Then the wishes contradict each other – at least if the zoning plan allows only the dormer but not the cross-gable. You would have to set back the "dormer" from the eaves line in order for it to be a real dormer without quotation marks. However, in doing so, its lower end would inevitably also shift upwards along the roof and thereby (if the knee wall of 150 is retained) enter the range of a pointless parapet height. Besides my previous suggestion, you could alternatively proceed by omitting or lowering the knee wall and then working inside with a short wall, on which you then set a real dormer. Taking an example knee wall of 75, then with a roof pitch of 35° the intended parapet height would be reached about 65 cm inward; with this as the short wall height, I would be satisfied in your place. Consider whether that would be a workable compromise.