Alignment of house on property

I have read my way through the internet and found many who complain about how chaotic and unreliable Danhaus is... That worries me a little.

The internet is chaotic and unreliable too, the more you browse it. Put your worries aside and get advice from the "prefab house expert" (whether this company, which additions to the construction contract, then shell construction and acceptance inspection). If you choose another company, then look in their catalog (I’m happy to help at that point too). Building proposals with three children's rooms are rare, so you would probably have to make adjustments following the three described approaches.

Just as a note: Staircase with landing should be planned with approximately 3! meters in length, kitchen access and passageways with at least! 80cm. 2-meter high doors do not fit under a low sloping roof, etc.

Thank you! Mh, the empty space would be filled by a stationary bike and at Christmas by the Christmas tree. Because now it always stands in front of the patio door, which only works so-so. But you are right, it is probably a bit oversized like that. I have to think about rotating the house first, I would actually like it facing the street lengthwise, I am a bit biased because our current house is positioned similarly and I don't like it. Without an expert, I definitely will not undertake this project, it's too big and expensive for me ;)

Just as a note: Landing stairs should be planned with approximately 3! meters length, kitchen access and passageways with at least! 80cm.
2-meter high doors do not fit under a low roof slope, etc.

I have understood that by now :)
It can also be a spiral one.
Otherwise, I actually did not pay attention to the dimensions, thanks!

Just a note: Landing stairs should be planned with approximately 3! meters in length, kitchen entrances and passageways with at least! 80 cm.
2-meter high doors do not fit under a low sloping roof, etc.

"Landing stairs" are effectively usually about three quarters of the landing depth "longer," and the mental disregard of setbacks (and roller shutter boxes) near sloping roofs is a classic mistake of amateur planners.

I have to think about rotating the house first, I would actually prefer it lengthwise to the street at the front, I'm a bit biased because our current house stands similarly and I don't like that.

Similar in what respect: related to orientation to the street or to the cardinal directions?

I will not undertake this project without an expert, for me it is simply too big and expensive.

Note that not only for construction supervision, but also for contract review. I always recommend colleague Beuler specifically for prefab houses, even though we have opposite views on one issue (whether to order the basement separately or together). But I am also happy to help find alternative house models myself, I never come to Berlin too often ;-)

Similar in both respects, here is the cadastral excerpt of our current home. The right part of the building is the old structure, and on the left we have added an extension. At the transition, from the top of the plan, is the entrance door. The kitchen is in the north and is actually somewhat dark, which is somewhat balanced here by the large window front. But it becomes incredibly warm due to the full south side; even on the terrace it is not comfortable on hot days.