Please assist in thinking about the floor plan of a single-family house

Dear forum,
I have been a silent reader for years and now ask you for your input. Attached you will find the floor plans as well as the site plan. Overall, we are satisfied, but we are complete novices and perhaps blind in some respects. Our challenge is to accommodate, in addition to 3 bedrooms, a guest room and an office, and also to have a small storage room (in addition to the attic) without a basement. Thank you in advance for your critical feedback.

Development plan
Plot size: approx. 700 m²
Slope: see contour lines (distance between lines: 1 meter)
Site coverage ratio: 0.35
Floor area ratio: 0.7
Number of floors: 2 full floors
Orientation: see plan (attachment)
Eaves height: 6.5 meters
Building height: 9.5 meters

Clients’ requirements
Style, roof shape, building type: single-family house, simple/classic, gabled roof
Basement, floors: no basement (due to soil contamination with arsenic + copper, increased disposal costs), 2 full floors
People: 2 adults, 2 toddlers
Room requirements: 3 bedrooms, guest room, office, bathroom, guest bathroom, storage room (laundry, ...)
Office: small office with 2 desks
Guests per year: several days per month, sometimes many days in a row
Open or closed architecture: closed
Conservative or modern construction: conservative
Open kitchen, kitchen island: closed
Number of dining seats: 6-8
Garage, carport: carport

House design
Planner: architect from the construction company
What do you particularly like? Why?

[*]Accommodation of the desired rooms (albeit at the expense of a larger circulation area of an inner corridor)
[*]... undecided: utilization of the east and south side (small seating area in the east + terrace in the south) is good, since we get up early and go to bed early OR possibly mirror the floor plan is better, as it seems that a south-west orientation is always “recommended” (?)

What do you not like? Why?

[*]dark corridor; a brighter corridor with this room program probably only possible with a larger footprint or relocation into the living area, which we personally do not want; therefore: arrange windows and doors in the storage room, office, living room in one row so that a bit of light can come in (?)
[*]access to the kitchen only through the living room; possibly a second door (sliding door) from the corridor into the kitchen and open the other door into the living room (?)
[*]possibly awkward guest room next to the technical room, as it might be too noisy (?)
[*]possibly revise the arrangement of windows in the children’s rooms (?)

Price estimate according to architect/planner for house + foundation slab: move-in ready approx. €380,000 - 400,000
Heating technology: air-water heat pump

Subsoil contamination with arsenic + copper, increased disposal costs)

Could you please be more specific about this? From what depth is the subsoil contaminated and with what type of arsenic?

Could you please be more specific about this? From what depth is the subsoil contaminated and with what type of arsenic?

So far, there is only one report for the entire construction area with three test drillings. It is assumed that the rock is geogenically impregnated with copper and arsenic-containing solutions. Regarding waste regulations, relevant contaminations >Z2 are expected from about half a meter below the surface. The topsoil in the planned construction area shows arsenic concentrations within the critical value range for the children's playground scenario. However, the critical value for the residential area scenario is not exceeded. It is recommended, though not mandatory, to build without a basement and to remove the topsoil in the construction pit area and store it for reuse.

The staircase destroys every room every room has a corner or a limitation. I would mildly say throw it in the trash with it.

The staircase ruins every room; every room has a corner or a restriction. I would mildly say throw it in the trash.

Thank you for your honest feedback! So in your opinion, should we rather plan with a staircase like in the attachment (on the exterior wall) and realign the floor plan accordingly?

With regard to the size, quite a bit should be possible. However, the arrangement of the rooms is completely baffling to me. The kitchen should be closer to the terrace than a guest room, right? If this is the result of extended consulting services, I wonder whether your wishes are so specific or the planner is so unmotivated? I would start from scratch.