New single-family house in southern Germany

Since a custom-designed house probably isn’t worthwhile for us, walls and stairs are fixed anyway and only changeable through a completely different floor plan.

May the plot share your hope of not requiring an individual design either. In the "modular system," extensions are unproblematic linearly in the ridge direction (with "solid" houses preferably n x 50 cm, with "prefabricated" houses preferably n x 62.5 cm) and shifts of non-load-bearing interior walls. Rotating stairs in the running direction with otherwise unchanged construction is also easily possible, as is closing off air spaces. Knee wall raises are easier than changing roof pitch (but caution: above an "ideal height" of about 1.0 to 1.25 m clear height, this comes with consequences for the windows!).

For every floor plan you like, you draw in your furnishing.

"Always gladly used again" in sample floor plans is the disguise of tight areas by reduced-size furniture symbols :-)

May the plot share your hope of not requiring an individual design. In the "modular system," extensions linear in ridge direction are unproblematic (preferably n x 50 cm for "solid" houses, preferably n x 62.5 cm for "prefabricated" houses) and shifts of non-load-bearing interior walls. Turning stairs in the running direction with otherwise unchanged construction is also easily possible, as is closing air spaces. Knee wall height increases are easier than roof pitch changes (but caution: above an "ideal height" of about 1.0 to 1.25 m clear height, this has consequences for the windows!).

"Frequently welcomed" in sample floor plans is the camouflage of tight areas by downsized furniture symbols :)

The dollhouse furniture that conveys spaciousness is correct.

I’m not worried about your financing, but about your mental and emotional health when you get preached to in the same thread in both ears about what to make of your plans – simply because the composition of the discussion community here in the foundation area is completely different from that in the financing area. In one area your vest has to be bulletproof, and in the other stab-proof ;-) So you basically have to keep one ear closed alternately, otherwise you’ll go crazy when someone tells you in one ear: "turn your staircase out of the dirt area" and in the other: "my gross-net calculator says your calculation doesn’t add up."

I just had to laugh very, very hard, thanks for that! :D

Could it be that posts cannot be edited afterwards here? If they can, please tell me how, then I will edit it into the first post.

Regarding the development plan, we only have the graphical part so far; I need to get the full text these days. Our plot would be number 17, no major restrictions are noted here. Since it is hard to read in this size:
Floor area ratio 0.4
open development single-family house and duplex
maximum 2 full floors
maximum 6m above single-family house
SD, WD, half-hipped roof presumably 20 to 45 degrees
Orientation of the buildings seems not to be prescribed at least in the first part of the area (built 6 years ago), they stand rotated in all possible directions

The two undeveloped plots to the west (368, 369) belong to the garden of plot 367 so we have an unobstructed view in this direction. Location is on the edge of town on a hill.

From the plot, a rough layout results for us
- Carport in the southeast corner with rather small driveway (1 car length)
- House in the northeast corner, presumably then next to the carport
- Ridge presumably oriented east-west, deviates overall only about 20 degrees from the axis
- Terrace facing southwest in front of the house so that you get the free sun in the evening

Since a custom-designed house probably isn't worth it for us, walls and stairs are fixed anyway and only changeable through a completely different floor plan. Accordingly, such discussions should hopefully be avoided here. But I think I'll change that again this evening

This line of thought doesn't make sense to me. No one determines YOUR stairs or floor plan. It's more reasonable if you—always considering the building regulations—first put together what will strongly shape your daily life, namely your floor plan. My feeling tells me that buzzwords like KFW, smart home, power storage, etc. are much too early in your mind and could therefore mislead you. Start with the floor plan; this will also reveal the sensible type or orientation of the stairs and further details. If you hope to plan it a bit smaller and simpler than others because it "isn't worth it"???, you are mistaken; we would all like that, and ultimately it costs us all a lot of money. Everyone, hopefully including you, wants to build a house that is beautiful for themselves. "Gimmicks" like smart home, garages, KFW standards, power storage come only at the end; these are not absolutely necessary for living. Therefore, I would actually also assign the topic of budget a high priority; you should clarify this very precisely. If you read here longer, which I would recommend to you, your opinion will certainly change... in your interest! I can always recommend pencil and graph paper for planning; we have hundreds of corrections and sheets here. On the internet, you’ll find countless suggestions; you can already pre-sort there. You can only edit for 20 minutes (at the bottom edge), after that it’s done.

As I said, for us building is more of an alternative to buying than the long-held dream of self-realization. Of course, it is nice if we can still accommodate a few wishes like a reasonable home office. But otherwise, we don't have any specific ideas of what absolutely must be included in the floor plan. At first, I see little reason to deviate from a standard floor plan with living/dining room facing south and kitchen in the corner and build something that isn't already offered as a standard floor plan by a manufacturer. That's what I mean by "individual planning is not worth it." Even with completely free planning, we would end up relatively close to such a floor plan.

PS: I have been reading for the last few evenings. There is quite a lot here in the forum ;)