Single-family house with staggered floor, southwest location in Bonn

Without having read everything, I would swap the living room and kitchen. Then you can have peace in the living room and have a large great area with guests. It spreads out better this way, because some sit at the table while others stand in the kitchen.

What the forum colleagues want to explain to you is that many projections, bay windows, "additions" mean many partition walls that must also be load-bearing at the same time. So structurally significantly more complex. So significantly more expensive.

There is no proper space for the wardrobe on the ground floor; with 4 people, it adds up.
Could it be that there is no window in the ground floor bathroom? I would definitely install one there.

We will look at that again

The slanted wall/door to the kitchen is a disaster and essentially only a makeshift solution, which you wouldn’t expect from an architect.
The living room is a ballroom but doesn’t feel like one. Our living/dining room is 52sqm and that is already very generous.

Why a makeshift solution? We liked the idea beyond the cost planning to connect both areas so fluidly. Putting a corner with a DOOR back in now is then too many corners again? As said, a small grand piano should also go in there.

The upper floor is a disaster, far too convoluted. We have slightly more square meters upstairs than you but have separate parents’ and children’s areas. I would never want my bedroom next to a child’s room.
I would seriously reconsider the trapped bathroom upstairs, especially if you get up at different times in the morning.

That loud? :P Well, I’m not so happy with the situation either. Maybe there is a variant where you swap the bedroom with the bathroom. Otherwise a better idea.
I find that the children’s bathroom etc. arises automatically because of the north side and the entrance and staircase, which are also based on the plot.
I don’t think the hallway etc. is perfect either, but it’s really not that bad at the end of the day. At least we use almost the entire area upstairs as living space and not as hallway space.

Laundry was also mentioned. I would install a laundry chute over the utility rooms with a drop flap to the hallway in both the upper and ground floors. My wife didn’t want that at first; today she doesn’t want to miss it...

My wife probably still needs to be convinced.

You mentioned construction costs including additional costs of 900,000 EURO; I think it will be significantly higher. The house is a Porsche in terms of statics...
We have 20sqm less living space than you, built in 2017, and also no simple static structure. We are now seven-figure, house including garden landscaping, and we have no pool. Note that we did a lot of the work ourselves and sourced material at purchase prices in some trades.

We were promised just under seven figures, possibly slightly over. The basement is also included. We’ll see. According to plan, we hear that number quite early.

Question, why does the current plan differ so much from the hand-drawn one?

We still assumed BO2019 and 75% area without setback then.

Do you have exterior views? I would be interested, it probably looks nice. Regarding the floor plan: I think the staircase is in the wrong position, which results in that very long hallway upstairs and the dark dressing room. If you moved the staircase, you could divide the upper floor much more harmoniously. On the ground floor, the staircase position also works and it creates space for a large wardrobe and/or pantry/utility room with a passage to the kitchen.

Definitely thumbs up for the effort.

Interesting thought. Our idea was that we would like to have the parent area by the terrace because we would use it the most, especially in the long term.
Below, the passage from the garage through the utility room would be cut off, and upstairs the utility room. In general, the stairs to the north would even make sense, but actually I think it's okay this way too because now upstairs in the narrow area to the north are only the utility room/ironing room and the kids' bathroom.

I can also post exterior views sometime.

We just had the appointment, a few minor things will still change. I still don’t quite understand the problem with the sections. For each of these sections, the Revit program can apparently display a cross-section of the house. Generally, Revit is pretty cool because you can also generate views from a point inside the house.

What still surprises me is what everyone has against the transition between the kitchen and the living room. They already overlap slightly and making it simply rectangular now looks more inconsistent.

because we would use it most likely

For the cigarette afterwards or for what???

No one will use this terrace, believe me. More likely the teenage kids when they want to be left alone by their parents. But then a child unfortunately has drawn the short straw.

I would at least save here and plan a flat roof, no terrace. I don't know anyone with a garden and kitchen on the ground floor who uses a balcony on the upper floor.