New single-family house approx. 190m² with double garage without basement - Design No. 3

I think the panorama with the "tunnel" into the terrace was deliberately chosen because it was seen somewhere. However, one should check whether the room in the photo is not rather 6 meters or more in width.

Above all, it blocks the western sun from the terrace. So in the evening after work, you sit in a dark tunnel instead of enjoying the sunshine. I find that completely absurd.

Budget
Bavaria is not the same as Bavaria. Bavaria can be very rural with corresponding prices. For example, I could imagine Oberpfalz being partially cheaper.
But yes, it is very ambitious, especially with the 40+ equipment I rather see 440,000 without garage. Earthworks are also higher at 90 cm.
Own contribution is not mentioned and much depends on the equipment.
Have you already matched the construction service description with your wishes?

Regarding the floor plan.
Be sure to draw all the furniture to scale and consider the space needed for occupied chairs at the table.
11 m length for the open space is fine, we have that too and it doesn’t feel like a hall, especially due to the large glass front facing the garden. But our room is wider. Yours is too narrow.
The design element for your terrace could take a lot of light inside and you will very often sit outside in the evenings.
Swap the children’s and parents’ areas on the upper floor. Children need light, parents less for sleeping. I would plan the study room larger.
Laundry should be upstairs where it is generated, for that the playroom can be a bit smaller.

Thank you for your answers and suggestions.

I wanted a partially covered terrace, so this proposal came from the planner.
Do you really think that the 2.5m walls darken the room that much? Would it help a lot to open the side walls?
Regarding the evening sun, we have already thought about it, but I was under the impression that the sun disappears behind the bay window anyway.

In the first plan, the children's and parents' rooms on the upper floor were swapped. Unfortunately, this solution was too tight because of the stairs.
We don’t find it that bad that the children's bedroom is now located in the northeast. Our child only stays there at night anyway.

Of course, we would prefer the living area to be 5m, but then the house would become even bigger, or we would lose some storage space.

Maybe one of you has some ideas on how we could change it.

Regarding the construction costs, I based myself on the initial specifications of the first two drafts. These were similar in house size.
The new specifications are currently being planned.
We are planning quite a bit of DIY work (such as electrical, flooring, painting, drywall, landscaping).

No bigger. Our all-purpose room is almost 6 m wide but only 10.5 long. Overall, our house is not bigger. You have much more hallway. Different stairs, smaller hallway, storage room gone, all-purpose room bigger. Upstairs utility room, smaller children's area, larger study, swap children's area and parents' area.

I wanted a partially covered terrace

And why then with walls? Why not a narrow pillar that supports the roof?

Why not combine the 2 storage rooms in the garage and directly next to it in the house into one and use it as a utility room? It would then be large enough to also store the garden tools, and you could enlarge the pantry around the utility room, so you get a big storage room there. Or move the toilet into the former utility room.

Then you could either let the kitchen run around the corner or simply make the open-plan room half or a full meter wider.

Do you really think that the 2.5m walls darken the room that much? Would it help a lot to open the side walls?

Yes. The corners and walls actually block the sun. You can plot that for each season, showing where the sun would be at 12, 15, 18 and 21 o'clock.

We don’t find it so bad that the children's bedroom is now located in the northeast. Our child only stays there at night anyway.

Uh... I would expect a bit more foresight from my guardian, even if I am not asked. The child spends more time in the children’s room than you do in the bedroom,