Corner plot with a granny flat

Concept approach to move away from the Anstattvilla "as big downstairs as upstairs," to make the upper floor almost like a staggered floor and the ground floor big enough to be shared "like siblings."

That's exactly what I've been doing all along – getting away from the Anstattvilla with a staggered floor, which, by the way, gets a gable roof here.

as more special shapes.

That’s also true. Special shapes are more expensive than a compact house build when it’s about the same living area. You are planning 30? sqm + more than needed, and those cost 80-90000 after all.
A cold roof doesn’t cost the earth, so it’s relatively inexpensive, even considering that you have to roof all 130 sqm. So if you only have 70 sqm upstairs but 140 sqm footprint, then only 140 sqm need to be roofed, but that is split over one and the other floor. It costs a bit more, yes, because the one roof has to be connected to the facade waterproof, but that shouldn’t cost more than one sqm of living space (Warning: not fact-based, just common sense).
And if you get a real added value with a small finesse of a few thousand euros, you take it.
(e.g., the garage/carport version, which is somewhat more expensive but suits you exactly here if the garage and parking space are important to you – only unfortunately I didn’t recognize the distances).

I took another look at the architect’s floor plans. It may be that he is currently in the exploration phase regarding the programs. We don’t want to overrate that.
Because actually, if you consider it this evening (with a glass of wine), he did quite well. Yes, it’s far from perfect, but it doesn’t have to be perfect at first draft or second, and let’s assume he doesn’t know the budget or had a bad day on the upper floor: The main living unit must be changed. Even though a 50 sqm parent area is cool. It’s not within the budget.
He should also clarify whether a garage is allowed outside the front garden, to which the main apartment’s entrance is attached.

So I understood it to mean that with the prefabricated house provider—actually a large rectangular house is cheaper—than more special shapes.

That applies regardless of construction methods, but they are no "more special shapes": in the example from there are two simple houses placed at a right angle to each other, both with rectangular floor plans, one with a gable roof and the other with a shed roof.

I have been doing that all along—with a step away from the AnstattVilla, which incidentally has a gable roof here.

Then don’t say it wouldn’t work.

I looked again at the architect’s floor plans. Maybe he is currently in the phase of finding the programs. We don’t want to overvalue that.
Because actually, if you look at it tonight (with a glass of wine), he did quite well.

As for the substances I would need besides wine for this friendly judgment, I gladly avoid them. He didn’t do well with either design, and side by side they look especially lacking in concept.

The main residential unit needs to be changed. Even if a 50 sqm parents’ area is cool. It’s not within the budget.

I find the parents’ suite especially unsuccessful in the "red" design.

Because actually, when you look at it tonight (with a glass of wine), he did quite well.

I already mentioned that might have been my fault: I just said: "let's try swapping the residential units" "it's too small" "another 2nd garage"

Even if such a 50sqm parent area is cool

Yeah, it has something. But it really swallows too much money and it still has to be cleaned.

He should also clarify whether, outside of the front garden, to which the entrance of the main apartment is linked, there is also allowed to be a garage

The one back there in the garden. Then we'd rather do without the 2nd garage and build a nice garden house. Cars are made to be parked outside anyway. Maybe I'll call the building authority and ask very simply about the garage and that stupid 1m distance. Although explaining that by phone - can you also send emails? "Back in the day," people just went to the town hall without an appointment.

I find the master suite particularly unsuccessful in the "red" draft.

I never really looked closely at the upper floors because the ground floor seemed more important to me.
We probably wouldn’t want a walk-in closet anyway—unless we had too much space left—which I would rather give to the children.
I never liked the T-solution either.
Well, I still have some ideas for the upper floor.
If only I knew where which stairs end.

I never really looked at the upper floors closely because the ground floor seemed more important to me [...] Well, I still have some ideas for the upper floors If only I knew where and how which stairs end.

These are self-resolving problems if you plan the upper floors first and think of the stairs from the exit point.

We probably wouldn't want a walk-in closet anyway—unless we had too much space left over—which I would rather give to the children. I also never liked the T-solution.

With some architects (and especially "architects") you have to have them "read back" what you said, just like in air traffic control.

Then don’t say it’s not possible.

I’m not saying that at all. What do you want?

I never really looked closely at the upper floors because the ground floor seemed more important to me

Well, you want to feel comfortable upstairs too. With 4 people, the time spent should be able to be distributed.

We probably wouldn’t want a dressing room anyway—unless we had too much space left over—which I would rather give to the children.

Yes, that gives options.

I never liked the T-solution either.

Neither do I. It can be functional; it becomes stylish through tiles and such.

If only I knew where and how each staircase ends.

The staircase position should not be underestimated. That shows that a standard position always works well.