Floor plan design single-family house with around 150 m²

Yes, in principle there are of course these main facades - but in practice usually not

??? Whether rectangle or L-shaped, almost everyone builds floor plans with parallel walls. Bungalows often have hipped roofs, so eaves all around. But your case - rectangle with a gable roof - is not exactly exotic. Two gables and two eaves, we subtract the north side as a potential winter garden side, leaving three in total. And hardly any floor plan - including yours - is equally well suited to all three, to meaningfully and harmoniously attach something.

Brief update: we now have the building permit. It was approved, only the terrace had to be removed because it extended into the 3m boundary area...

Otherwise, we will now get an offer for a central controlled residential ventilation system. Hopefully it won't be too expensive - the fireplace planning is still pending.

We are also still considering how to place the 2 parking spaces. Next to the house is a big waste of space, as 5m in front must be kept free. It would be nice to use the space directly at the driveway, maybe just to cover 1 parking space.

Now I just heard from my partner, when we were standing in the almost finished house, that she would like to go directly from the kitchen to the living room without a big "detour" around the dining table. I think a small table would work, but when it’s extended and more guests are there, it’s really difficult to get to the sliding door, which unfortunately is located where the table also stands. There must be at least 1 m of free space to still easily reach the sliding door, I think. She was quite shocked by that. In hindsight, I might have placed the piano somewhere else earlier, for example not made the fireplace so big, and instead made the sliding door wider (e.g. 3.5–4 m) or installed an additional door next to the sofa. I just hope it doesn’t get too tight around the dining table, what do you think? I thought about placing the table about 1 m away from the sliding door, crosswise to the window as drawn in the picture, but then the passage between the chair and the piano is already quite narrow... or are there maybe better options for placing it? We also considered a round table... Unfortunately, the architect didn’t point out this problem to us and it wasn’t really one here in the forum either, maybe in the end it isn’t one, but my partner has driven me a bit crazy over it now... Attached again is the floor plan of the ground floor with the "problem".

What speaks against turning the table by 90° and placing it somewhat towards the fireplace?
Crosswise it gets a bit tighter from 2m onwards, but it is possible.
When you extend it to 3m, you usually have limitations anyway; at least very few dining areas are so large that you don’t have to take a small detour there.

I personally would not be ashamed to turn the table a little out of a "straight" position, but I am amazed that after all the eternal crumb cleaning you are only now involving such a significant part as a life partner (?)

What speaks against turning the table 90° and placing it a bit towards the fireplace? It gets a bit tighter from 2m when positioned crosswise, but it’s still possible. When you extend it to 3m, you usually have restrictions anyway; at least large dining areas are such that you don’t have to take a small detour.

If it is placed further towards the fireplace, you have less passage width there again. I also think that crosswise it works up to 2m. Lengthwise maybe more. But maybe it’s not that important, as you already said, that not everything has to be perfectly accessible in large dining areas. Although 2.4m, for example, isn’t that much either; you can only just fit 8-10 people at the table. I wonder what others do when more people come.