Others can tell you more about §34. It is not a free pass.
The best thing about §34 is to set the red-light district as an aerial image to see how the neighbors have built. You have to adapt to them with certain parameters.
However, I must say that 1. the staircase on the ground floor is not identical to the staircase on the upper floor: on the ground floor it is supposed to have 243 cm distance from the outer wall, but upstairs it is about 170 cm or less. Actually quite easy to recognize at first glance. Then the "important" load-bearing walls parallel to the staircase are not aligned above each other. You can do this with additional structural effort or use lightweight walls upstairs. Just a hint.
We are aware that the open design with an open hallway and void space entails some sound transmission.
We prefer an open, modern design.
But I think you have no idea what you actually drew?! You have a corridor that is dark, and apart from the front door there is no light. The two long corridors next to the staircase are over 3 meters long. That is already top-level in misunderstanding openness. They are and remain two long narrow corridors that reinterpret the word "openness." There is nothing modern about such tubes either. Our old farmhouses were designed like this. Although their staircase is somewhat more on one side, your doubling does not make it better. And then let's look at the upper floor: while the type house, which serves as a template, at least still has one side of the staircase with an open railing, you have walls on both sides there. That would be a third tube, which you certainly don't want if you want it open. The crowning achievement, however, is the void space. It is walled in on the upper floor (not in the template house). This causes it not to be loud upstairs, but the corridor also cannot benefit from light: it simply has none.
So you can say: the first impression is gloomy and confined by walls. The walls are good for nothing, they elongate the building shape and confine.
But you also leave no mistake unmade: garage in the south at the same level as the house, but then with an overhang at the terrace to block light again. Carport then at the other corner... You leave no blunder out.
We are especially interested in your no-gos or criticism points where you think we would strongly regret them later.
Well, if openness is so important to you, you will regret this house. Yes!
What do you particularly like? Why? The open design
Here again. So, it may be thoughtlessness that you drew it this way. But it really would be a tragedy if a general contractor tells you that he can build it this way, then has it redrawn for a building application, and during the shell construction you recognize your disaster for which you are responsible.
About the house/plot itself: wrong house shape, in my opinion. On this elongated plot with east orientation, an elongated house would be more welcome. Double garage or combo in the southwest corner so that the plot is sufficiently shielded from the ugly wall and sunlight comes into the house here. The ugly wall can be clad on your own property or planted green, it's not rocket science. This brings air and brightness into the house, even in winter, and that regulates openness. If you then add a window that illuminates living rooms from the west, there is enough openness. A staircase placed as a barrier in the middle of the house is again counterproductive. It blocks light instead of letting it through. Or place the garage in the northwest and build a cubature alternating between one and two stories, where the garage is integrated so that there is enough area facing south.
A house will not become Bauhaus just because you give the cubature a simple form. I simply assume that you like modern flat-roof houses. But they do not grow in aesthetics with the cube form, but rather with offsets, overhangs, and a play of one- and two-story cubatures that visually form a unit.
P.S. I count almost 90 sqm on the ground floor. What was the budget again?