Ground floor approx. 100 sqm, upper floor expandable (planned bathroom, 2 children's rooms, 1 storage room)

Nobody here understands the thing with the back entrance anyway except those who grew up in rural SH. Not even Yvonne, who’s kind of a Hamburg native and therefore out. Our front door is almost always locked too, the back door always open. Everyone, everyone, everyone, and often people come and take the back door.
About the kitchen: If you mainly eat in there, then the distance to the living room doesn’t matter anyway, because you only very rarely drag anything into the living room. If you like it that way, then just leave it. The bowl with red cabbage, the mixed roast left and right, sauce and Linda potatoes, if it’s time for that, the few meters can be carried together.
That the “good” table is also used as a table for things other than food is quickly forgotten by some. My wife sets up the sewing machine there. The granddaughter sits there and fiddles, at Christmas I joyfully set up some of the model railway on it for the kids, so naturally the food was skipped, the daughter had to pay for that. So, a table like that in the living room is really good.

The thing about the hallway and the straight stairs eating up space is true. If you want to think completely new, try this. You can leave out a room and instead make something else bigger. Karsten

So this floor plan is really rarely bad. A huge hallway to "go around the corner" in the outermost corner of the house to get to the living room. From the sofa to the kitchen fridge then a small hike. The bedroom and living room walls do not look parallel. In the kitchen, a 1m wide window facing north, so you need a lamp during the day to see the food. The bedroom also stays dark. For me, more of a floor plan like from 100 years ago, I would also think about the resale value.

Best regards
Sabine

No, I live in a village... even a chicken breeding comes from there [emoji16]

Nobody here really understands the backdoor thing except those who grew up in rural SH. Not even Yvonne does, she's already kind of like a Hamburg native and therefore out. Our front door is also almost always locked, the backdoor always open. Everyone, everyone, everyone, and often some come, take the back door.
About the kitchen: If you mainly eat in there, then the distance to the living room doesn’t matter at all, because you only rarely drag anything into the living room. If you like it that way, then leave it be. The bowl with red cabbage, the mixed roast on the left and right, gravy and Linda potatoes, when it’s time, you can carry these few meters together.
Some quickly forget that the "good" table also serves as a table for things other than food. My wife sets up her sewing machine there. The granddaughter sits there and fiddles; at Christmas I set up something from the model train on it to the children’s delight, so of course then the eating didn’t happen, the daughter had to give way. So, such a table in the living room is really good.

The thing with the hallway and straight stairs taking up space is true. If you want to think completely anew, try this. You can leave out a room and instead make another bigger. Karsten

That may be true that there are certain regional customs. At my grandparents’ none of them went through the front door either, but everyone immediately went into the garden through the patio door.
But something like that is a luxury you have to be able to afford. And in my opinion, this floor plan cannot afford to waste valuable space with a door that’s basically unnecessary.
The same goes for the dining table. Sure, it makes sense. But you have to be able to afford the space.
So either the floor plan is heavily revised again, or reduced in some areas.

The hint has already been given that one has to see whether the budget will still be sufficient for an expansion. To be honest, I am rather pessimistic – once a child is there, the money will be less and the general living costs will likely increase. I find it rather hard to imagine that there will eventually be money left for an attic expansion. In addition, the garden has probably not even been financially planned yet. Especially with a child, it will have to be finished at some point.

Why exactly should there be so much floor space? Wouldn't it be an option to build significantly smaller and plan the attic accordingly right from the start?

Maria, land is cheap here. Curly, the floor plan is not rottenly bad, but you find it rottenly bad. While others, like me, find it very good.