Floor plan single-family house 110m² - ground floor + upper floor - first draft room layout

You have to be able to afford a children's bathroom. (Financially and in terms of space) I had asked our architect back then. He has 3 children.
1st question: Do you like cleaning?
2nd question: Do you have at least 5k left in the budget?
In his experience, the bathroom is used too little and he advises against it. He would never build it again.

You can't reduce the hallway on the upper floor much. Maybe you can save some space if you cancel the children's bathroom and rearrange the rooms.

In the basement, we want the kitchen and dining area on the south side,

the living room further back

I am already struggling with the mention of basement when a cellar is involved. But I won’t complicate things and instead assume the ground floor where the kitchen and living room are desired?! But where is south, where is back? What did the planner not consider there? Is “down” south??????

I’m trying to get the measurements, my main concern was optimizing the layout of the rooms.

Exactly: for optimization and constructive solutions the information that is coming in bits and pieces is important. Apparently this is a two-story building, where an attic is not to be expected? Or is there a roof that could be converted later on? Could the cellar get a light well so that expansion potential would be possible here? By the way, the cellar is important for structural elements, the attic for the staircase! Therefore: fill out the questionnaire!!!! 110 sqm is, to be honest, not a wish concert. What strikes me: what are the cupboards in the bathroom for? Why have a pantry there if a cellar is present?

So I cannot confirm that a baby bath is not used. We have one and I love it. However, our two older children are already going through puberty and it is a real blessing! As long as the children are small, it is hardly used, that is correct.

Welcome to the forum!

, are however not quite satisfied, as some of our wishes were unfortunately not taken into account. Accordingly, we are now disappointed, since this is going to be a "life project" for us and we feel a bit abandoned.!

This reminds me of buying a car with my wife. The salesman asked what wishes she had and she answered: "I wish for a car that is bigger inside than outside."
With the life project, there are a few decisions to make regarding your wishes. The first is whether a terraced house is the right choice, because the wishes won’t fit in if the result is supposed to be a practical and livable house. If due to location, opportunity, financial framework or other reasons a terraced house at exactly this spot is the right choice, then it makes sense to prioritize the wishes among yourselves and decide accordingly.
Based on the width of the terraced house, you can estimate whether a longitudinal separation of rooms on the ground floor is sensibly feasible. A tube-shaped living area with 2.7m width limited by a glass door will hardly become a frequently used retreat. A pantry on an exterior wall steals an extreme amount of daylight, which is inherently a bottleneck in a terraced house. A second bathroom is a great thing but costs you disproportionately much space upstairs. Also, the wish for a wood stove and a kitchen counter is space-intensive. The planner has listened to you and obviously tried to fit all of that in, that’s not the problem, since he didn’t clearly say which [wishes] to prioritize. Now there is no usable entrance, no natural light in the kitchen, a wood stove that is constantly in the way, a dining area that is just as cramped as the living area, and upstairs cramped living in favor of parallel shower options with partially difficult ventilation. When buying furniture for the bedroom, the restricted maneuvering space must be considered.
You are right, the design is not good, from my point of view even really bad. So set priorities or abandon the terraced house idea. Consider beforehand how you can include the basement and attic now or later. A pantry in the basement has already been mentioned – it is also temperature-wise advantageous.

So I cannot confirm that a children's bathroom is not used. We have one and I love it. Our two older kids are already in puberty, and it is a real blessing! As long as the children are small, it is hardly used, that's true.

That may be, the lifestyles are different. Nevertheless, it is a luxury and with 110 sqm it comes at the significant expense of other areas.

I don't think the upstairs is that bad - everything is just very small and tight. If the access to the small bathroom is from the bedroom, then you can create a nice little master bathroom out of it. It's not the desired wellness oasis - but how often do you actually take wellness baths with candlelight and all that fancy stuff,... The big bathroom could be slightly reduced in size and used as a children's bathroom with a bathtub.