Floor plan of a single-family house with 240m² including a 75m² granny flat and garage

For the general contractors, we would have ended up at 580K for the entire house,

As a shell house, so like you calculated it (finished downstairs and nothing upstairs)? Or did he calculate that you get everything with the necessary finesse? (Heating, plumbing, ventilation, shutters, and so on)

but I would be interested in what you would change about the floor plan

I have to agree with . I can mention that quite a few doors are poorly positioned, also that the granny flat gets better room utilization if the entrance is placed sideways, or that the common rooms should not be planned almost square, but if you already plan the guest room so poorly and it is clear that this room can hardly be used as a bedroom, then for heaven’s sake why don’t you plan this room better accordingly? There is enough space after all . .?! And why should anyone feel comfortable in a bathroom that isn’t even 4 sqm when they get older?

Did I understand correctly that you are planning these huge rooms alone, but have no family except for your mother who gets her own granny flat? Otherwise, yes, it is a row of rooms, most nearly too large anyway, since a 15 sqm children’s room should be enough for any child. A walk-in closet of 10 sqm where only three one-meter wardrobes fit due to poor planning. Just draw in the furniture once, then you will see one or the other planning error. Why the terraces are planned side by side with so much plot area is also questionable. And yes: sightlines and light are important. The former you get for free with good planning. Here there is nothing that is nice. You can’t even quickly wash your hands when you come home. And I bet: the kitchen gets the appetizing view into the guest toilet. Right?

The budget should be sufficient for the shell and the lower floor.

So after all: granny flat will be finished and you move into the guest room on the ground floor and the rest upstairs remains unused and is not finished. I don’t want to offend you, but you are single now, 36 (when you were planning in 2022, single at 34) and you will be 40 and single in your shell house with oversized rooms and won’t get out of it to date a woman because you are busy finishing for several years. I would plan a bit more realistically and have something smaller built, e.g., a module that can be expanded as needed. That will also be affordable initially.

Yes, you wrote it yourself. You, clueless, had the house modified by (k)no architect. The first big mistake. Have the house planned by a real architect. They have been trained for that. Trust me, even the worst architect wouldn't plan a fireplace in the stairwell. Yours seems to be absolutely terrible then.

The upper floor feels like a multi-family house. Partly difficult to furnish.

Why are you planning such a big house? It is only for 2 people.

Go to an architect and have your house planned. According to your budget and your key points.
Just draw furniture in the granny flat to scale with the necessary movement spaces. Does your mother really want a 90 cm bed and a small wardrobe? What is supposed to go into the chamber that is labeled as an office?

Believe me, even the worst architect would not plan a fireplace in the stairwell. Yours must be absolutely terrible then.

I don’t see the work of a bad architect here. If I base it on the planning virtuosity of the OP from his old thread, then I rather think: by now he will have found a sports or bar buddy who is a draftsman at a multi-story residential developer and cleanly redrew his sketches for him. He is probably similarly young and considers a 60-year-old woman old enough to find such social housing architecture sufficiently attractive. We are apparently dealing with the following situation here: Mother (60, single) owns a plot of land, son (36, single) hopes for improved chances with the ladies if he has a nest to offer, mother is willing to give the son the plot if she gets replacement living space.

Plot size: approx. 1300 (at least 1/4 for the granny flat)

Apparently the plot shown is meant, I don’t understand the addition. I suspect the plot is not free, probably currently inhabited by the mother (and the OP?) and thus not cleared; top right on the plan probably with a shed or garage (not intended to be demolished)?

Plot size: approx. 1050 (given, but must include granny flat on the plot)

My old post was but was now strongly delayed by personal, political and building authority issues, so it has partly changed positively and partly negatively.

The plot is apparently still the same as it was planned over in the old project; the gigantic house has only been rotated. The “partly positive changes” would be interesting.

How big / tall are the houses in the area?

The upper floor has something of a multi-family house. Partly difficult to furnish.

That was the goal. To make division into four units possible. At least that's what the OP writes. It looks like that too