Floor plan for a single-family house without a basement / 4 persons

Oh yes, I also wouldn't want to do without the shower downstairs. Longer bathroom and door from the hobby room around the corner..

By the way, I don’t understand quite a few things: 78.08 sqm attic is 85.32% of 91.51 sqm on the ground floor – that would mathematically be a second full floor. In the cross-section, the nominal ridge height is already slightly exceeded – so what is the reference height? Then you talk about 80 cm by which the house should be higher, which I cannot find in the cross-section nor does it answer my question of how you want to save the basement with that: that would be both an almost ideal base height for a basement without much light well digging, and a basement waiver would mean, according to my formula, 40% basement cost. So my impression cannot be that this is a detail-level imperfection. I rather see the homework still far from being done.

Again on the process so far:
1. Originally requested was a single-family house 1.5 (approx. 130 sqm living area) with basement and double garage. Personal meetings with Contractor 1 and Contractor 2 took place, building regulations etc. were obtained. Contractor 1 recommended to build a gas condensing device with solar thermal and without KFW 55, but optionally offered air-water heat pump with KFW 55. Contractor 2 discouraged me from the recommendation of Contractor 1 and offered only air-water heat pump with ventilation system (KFW 55). Contractor 1 was cheaper compared to Contractor 2. Floor plans (10.5 x 8.5 m) from Contractor 1 and Contractor 2 are attached.

2. Due to the average flood level, a waterproof concrete shell ("white tub") is necessary, and the house protrudes about 70-80 cm relative to the street. Entrance stairs are required, terrace sloping, knee wall 125 cm, rooms in the attic are in my opinion all too small, attic storage is unusable (well, there would be enough space in the basement).
My initial thinking: building the house without a basement is cheaper, less excavation, rooms become bigger, entrance stairs are omitted, more space in the attic storage, knee wall becomes higher? Think again! I sent my self-created beginner floor plans to Contractor 1 and he implemented it 1:1 without optimization. New offer from Contractor 1 was as expensive as with basement. Reason: house is now "much" bigger (12 x 9.8 m). "Details will be clarified in the working planning." To my dissatisfaction, the knee wall suddenly was 90 cm, which was justified by the plot ratio/floor space ratio and the 75% regulation.

3. Now I have taken the floor planning into my own hands or rather tried to. That’s how I came across this forum in the hope to get valuable advice and many eyes obviously see more than just two. So far you have really helped me a lot. Thank you very much for your valuable time! Maybe I should start again from scratch, look for a new contractor or architect and reconsider a basement again.
These are real dimensions of the furniture, which this online tool provides me. However, I only inserted the furniture as an "example," since I haven’t yet really thought about the future furnishing but only used the dimensions of our current living room and kitchen as a "reference." The large hallway on the ground floor still needs a lot of optimization, but I currently don’t know how to rearrange the rooms. The "narrow" storage room on the ground floor (posting #10) is 3.18 x 1.25 m. The dressing room also gives me headaches. Construct differently or leave it out entirely? My wife absolutely wants a large walk-in shower. The roof slope really doesn’t make it easy for me.
The bikes should only go in there during winter. Or on the wall in the garage, although a single garage without storage room is too tight. I will think about a single garage with storage room.
A door in the recess unfortunately also takes up space. I find large children’s rooms more important than a huge master bedroom. Since I only use the upper floor for sleeping, I gladly give up the square meters. I’ll reconsider the issue with the shower and moving the window in the guest room. Thanks to you!
I have taken your notes on the pantry and the distances into account in the current plan (posting #10). Thanks!

but I currently don't know how I can rearrange the rooms.

Leave that to the general contractor. Everyone understands if you want to build without a basement because of the price. I've said it before. Yes, it's a short sentence, and you don't need to say more than "let the general contractor do it first," then we'll see and optimize, for example the shower.

Good evening everyone,

attached are the new floor plans from the GU and the cross-section from a friendly architect. The freelance architect offers me the services according to the minimum rate according to the HOAI calculator. A precise design of the interior walls etc. will only be done after signing the architect contract. Between the budgeting / cost estimate of the architect and the fixed price from the GU, the architect would be about €10,000 more expensive, although I do not know what buffer the architect has calculated. My parents-in-law are currently building with the architect in the same construction area, which of course could bring certain advantages, e.g. when obtaining offers for a follow-up contract with the trades.

1. What do you think about the new floor plans from the GU? I am still not satisfied with the shower placement, but he suggested placing it on the 2m line, i.e. where the washbasin is currently located. Actually, I had planned the shower as shown in the picture "Eigenentwurf_DG".
2. If you look at the cross-sections from the GU and the architect, you will see different room and ceiling heights. Has the GU misplanned?
3. The GU offers me a central controlled residential ventilation system with heat recovery for €14,500, but advises against it, as it would not be necessary for KFW55. According to him, an exhaust fan in the bathroom and window frame ventilators in the other rooms would be sufficient. He has only installed a central controlled residential ventilation system in 3 out of 100 new buildings. The architect says that due to the low room heights, justified by building regulations, a suspended ceiling is not advantageous and therefore possibly recommends a decentralized controlled residential ventilation system or also window frame ventilators. After independent research, I found out that a central controlled residential ventilation system would also be possible in the concrete ceiling or in the attic. A further conversation with the architect is still pending. I do not feel well advised by the GU regarding the central controlled residential ventilation system. What do you recommend to me?
4. Despite point 3, the GU is well regarded and highly rated in the region. Satisfied homeowners have confirmed this to me in personal conversations. The GU contractually guarantees completion within 8 months from the start of construction, the friendly architect estimates 9 months. With the freelance architect, the final costs would of course be uncertain. Whether I would be cheaper in the end with tenders to individual trades than the GU, where almost everything comes from a single source, is uncertain. I have not yet made a decision because I am torn back and forth. Would you recommend the architect or the GU?

I am very grateful for every answer and every suggestion from you! Then I can also sleep more peacefully. :)

In case of doubt, I am always in favor of my own architect. Whether their heights differ, I cannot see in the drawings (?) - a cost estimate deviation of only 10 TEUR between the general contractor and the architect sounds good - for an estimate, that is practically a "zero deviation".

According to the GU’s drawing, the house is 8.11m high, and according to the architect, it is 8.56m high. I am currently leaning a bit more towards the independent architect, as she also plans/specifies the photovoltaic system, carport, and terrace. The GU does not do this, or only at outrageous prices, such as a 6 kWp photovoltaic system for 14,000 EUR! :D However, I must mention that the GU advised me to commission the photovoltaic system independently, as it is not their main area of expertise. What was surprising, however, was that both the GU and the architect consider the kitchen width of 2.50m and the living/dining area of about 7.50m to be sufficient. Some people in the forum recommended broader dimensions to me. More is always better, of course, but unfortunately also more expensive.