Single-family house floor plan 11.5 x 8.5 on 475 sqm plot

[ATTACH alt="Erdgeschoss.jpg" type="full"]50933[/ATTACH][ATTACH alt="Obergeschoss.jpg" type="full"]50934[/ATTACH]

Hello to the forum community.
A few weeks ago we received the approval to purchase a plot of land (No. 10) and are now considering how best to design our house. We want to build with a general contractor (GU) using solid brick construction. In 2-3 weeks we have some appointments with GUs who have been recommended to us by several acquaintances (from their own experience).
Now the GUs want a rough draft from us in order to create a concrete offer accordingly.

Some information about the pictures:
- In the development plan, the small triangle indicates the designated garage entrance.
- The development plan is oriented to the north - a small footpath borders our plot to the north.
- The windows are not yet fixed but only roughly sketched in.
- Most of the existing furniture, including the kitchen, is drawn to scale. The children's furniture will probably be rearranged several times. There should be space for 1 bed, 1 wardrobe, and 1 large desk; besides that, the kids will have to accept that a cabinet for storage of less-used toys will be added. The bathroom furniture is still flexible.
The dining room / living room layout with a frequently used PC desk is what we currently have, without adults disturbing each other.

Now we are looking forward to the feedback, questions, and suggestions from the forum community.

Development plan/restrictions
Plot size: approx. 475m (approx. 26,? x 18,?): not yet precisely measured
Slope: yes/no - approx. 80 cm drop over 26m
Floor area ratio: 0.3
Floor space index: no restriction
Building window, building line and boundary
Edge development
Number of parking spaces: 2
Number of floors: no basement due to groundwater
Roof shape: gable roof, orientation doesn’t matter
Maximum heights/limits: ridge height max. 8.7 m; wall height min. 5.0 m; wall height max.: 6.2 m
Further requirements: garage entrance fixed (viewed from the street, right side of the house)

Requirements of the clients
Style, roof shape, building type
Basement, floors: no basement; 2 full floors; storage space in the attic and in 1 garage (no second car planned)
Number of people, age: 2 adults (45, 35) 2 children (6 and 3) => no third planned
Space requirements on ground floor, upper floor: office would be nice, but absolutely not a must
Office: family use or home office: no separate office necessary (experience from the last 10 years)
Overnight guests per year: 2-3 times/year, each 2 persons
Open or closed architecture: doesn’t matter
Conservative or modern construction: conservative
Open kitchen, cooking island: large kitchen with dining area for 5 people, separate room with doors
Number of dining seats: kitchen 5; dining room: 4 with room to extend the table to 8 people
Fireplace: no
Music/stereo wall: no
Balcony, roof terrace: no
Garage, carport: double garage
Utility garden, greenhouse: no
Further wishes/particularities/daily routine, also reasons why this or that should or shouldn’t be:
- straight staircase appeals to us best / possibly also quarter-turn
- at least 2 washing places; better 3, since parents like to bathe and do not want to have to consider showers or toilet use of the other three
- entrance from the gable side; gable side faces the street, since width is limited: 6m garage + 8.5m house + 3m distance = 17.5m
- utility room is best suited from our point of view next to the garage as a (almost) windowless room - OR?

House design
Who is the planner: own design

What do you like especially? Why?
- straight staircase - just like that
- separate bathrooms/showers - no quarrels when two people get ready for the disco at the same time
- large utility room also for drying laundry and storage
- large children's rooms
What don’t you like? Why?
- conservatory desired (no suitable place found)
- high need for "storage space" on ground floor and upper floor due to lack of basement
- no vestibule
Price estimate according to architect/planner: The GU will see our plan in 2 weeks
Personal price limit for the house, including equipment: 350,000
Preferred heating technology: gas

If you had to do without, which details/extensions
- can you do without: straight staircase, conservatory, separate WC/bathroom on upper floor
- cannot do without: shower on ground floor

Why has the design turned out as it is now? For example
Own planning based on a mixture of many examples from various magazines...

What is the most important/fundamental question about the floor plan summarized in 130 characters?
Can the upper floor be modified so that a useful place for a small spiral staircase to the attic is created? Currently a folding staircase is planned - then the attic is only a storage room accessed about once a month
Can the attic be developed as an "actively accessible" storage room with the height specifications (ridge height, max. wall height at eaves side) and possible roof pitches (20-35 degrees)? We do not need more than 2.50m ceiling height on ground floor and upper floor.

Why two such large dining tables? I don't imagine a workspace directly at the dining table to be very nice; it's not always tidy, right? I would rather section off a corner somewhere so that bills or similar things don't have to be quickly cleared away when guests come. In the kitchen, there is also a lot of wasted space to the right of the table.

I also didn't understand the thing with the two dining tables. And the kitchen overall not at all. So much space for a single kitchen unit, which apparently isn't fitted properly either? It looks like an existing unit that's a bit too small?

I also don't find the two bathrooms upstairs optimal yet. The two rooms have a lot of open space, it could be more efficient. Perhaps a utility room could be carved out upstairs?

3 bathrooms for 3 people?
Dining spaces where in one of them the people are squeezed between the table and the cupboard?
No wardrobe for that, washing machine and dryer stacked on top of each other due to lack of space, the workspace squeezed into the corner.
Why not one less bathroom? Children can also use the stairs when getting ready at the same time.
Why not one dining space in an open-plan kitchen?

I have two more things: The topic of "storage space" seems very important to you. Do you currently live in a house with a basement, or do you have hobbies that require storage space? Of course, it is important to store things, but sometimes people just hoard items they don't really need. Unused toys can be stored in the attic, and then you can also give some away or sell them. Upon a second look, I still find your floor plan unbalanced. You waste space in some areas and have a cluttered dining room as a result. With all the cabinets and the additional desk, it would be too tight and uncomfortable for me.

Secondly: your budget is not exactly generous. Does it also include incidental construction costs and exterior work? Financially, I don't really see the conservatory in there.