Single-family house floor plan, 2 stories without a basement

The front door opens outwards, then you enter a cave in the intended storage space under the stairs, because there is no room in the door's swing area. Inside, you basically have no room to move. After the front door, there is an approximately 4m long tunnel to the living space; I don’t see that you have used real furniture dimensions there that correspond to the furniture you will use there, the round dining table will certainly not fit that way. All doors open to the wrong side, which has already been mentioned; the door widths are not marked or are simply drawn to look fitting. The sofa is squeezed into the corner; the living room apparently has only about 12 sqm. The fireplace near the TV could get too hot for that space, although such a thing seems questionable anyway with underfloor heating. Between the kitchen and the living room is a huge empty area that will hardly be usable; compared to the 12 sqm living room, this is not really favorable. The rooms on the upper floor, starting with the staircase that is also problematic for moving furniture, I consider a design for the round file. Long, narrow rooms, equally unfavorable doors/windows, and a bathroom that you shouldn’t build so awkwardly; in the bedroom you walk directly against the bed. I think that here a greater fundamental understanding of living spaces, doors, and other things should first be established.

Well, then draw all of that as a site plan clearly visible.

Regarding the house plan, the narrow windows and the narrow rooms also caught my attention. Likewise, the poor door positions and the lack of depth for the position of the wardrobe closet (only 110 cm room depth) are not effective with a 60 cm closet depth (which I always draw as 65 cm in raw construction dimensions).

At least for the upper floor, one could correct the doors as drawn.

It seems to me, by the way, that too much staircase overbuild has been calculated here again. This is always associated with the risk of hitting your head when going down.

In the ground floor, probably let the bathroom door open outwards. The study on the ground floor is also rather borderline if a sofa bed is to be pulled out there and still have a tolerable bed surface. That is usually 200 cm in length plus the rest of the sofa (armrest, etc.). A closet at the drawn position will then be rather tight.

At least for the upper floor, doors could be corrected as shown.

The door in the bedroom should also be moved close to the wardrobe. The door in the gym, which by the way I don't see as sensible in the south, can also be corrected. But there's still the tunnel-like hallway, which I personally find off-putting and needs to be corrected. I also noticed the squat living room. It can be done, but with 4 people the sofa is not sufficient. Additionally, there is the dance hall in the dining area. In the end, one would probably get a better design otherwise.

1.) we need to look over that again

When it comes to the budget, it’s best to calculate backwards: 500K / 3.2 ~ 156sqm. Accordingly, I would recommend comparing floor plans from prefabricated house suppliers in this size. This will give you an idea of what is possible for this amount of money. Rooms like a "gym" or the unused ballroom in the living room are quickly cut, if you ask me.

Apart from that, it is not your task to design your own floor plan. That is done by the architect or planner for you.

When it comes to the budget, it's best to calculate backwards: 500K / 3.2 ~ 156 sqm.

Should the ancillary construction costs be included?

However, the question has not yet been answered whether the ancillary construction costs of the calculated 30,000-50,000€ are included in the 500,000€.

In relation to your budget expectation, the draft is definitely too wasteful with square meters that do not provide any real residential benefit. Sure, having space is great – yet the priorities seem financially unfortunate, focusing on the hallways and the distance between the kitchen and dining area.