ᐅ Floor plan for a single-family home with 4 to 5 children's bedrooms

We are currently considering building a single-family home with 4-5 children's rooms and are looking for well-thought-out floor plans. Unfortunately, we have not yet found any floor plans that meet our wishes, building regulations, and budget all at once.
We are grateful for any tips and also welcome advice regarding individual rooms.

Development Plan / Restrictions
Plot size 2,000 sqm (0.5 acres)
No slope
Building area approximately 14x14 meters (46x46 feet), plus garage possible

Number of parking spaces 2
Number of floors 1 full floor
Roof type gable roof

Builder’s Requirements
Style, roof shape, building type
Frisian house, country house, single-family home, gable roof
Basement, floors no basement, 1 full floor or 1.5 floors
Number of occupants, ages 6 people: 48, 38, 7, 5, 3, 0
Space requirement ground floor, upper floor? Possibly 220 sqm (2,368 sq ft)
Office: family use or home office both, one study on the ground floor would be great
Guest stays per year rarely overnight guests
Open or closed layout open
Open kitchen, kitchen island open kitchen
Number of dining seats 8
Fireplace no
Music/sound wall no
Balcony, roof terrace no
Garage, carport double garage with storage room
Utility garden, greenhouse no
Additional wishes/special features/daily routine
We might need an additional children's room. Therefore, a guest room should be able to be converted into a children’s room if needed.
Two shower bathrooms plus a guest toilet would be desirable.
Since we plan to build without a basement for cost reasons, there should be a pantry next to the kitchen. The utility room (HWT) must not be too small; we have two washing machines plus a dryer. We have two very large beds that ideally should be in one shared bedroom (3.25 m and 2 m) (10.7 ft and 6.6 ft). The entrance area must have space for a bench, shoes, and coats for 6-7 people.

Financially probably not feasible anymore, but a "children’s living room" and a covered terrace would be great.

We were offered a plot of land at very short notice, which is really a stroke of luck in the current times. As you can probably tell, we have not dealt with the topic of new construction at all so far and unfortunately now have to decide very quickly whether this project is feasible for us.

About the finances:
The plot costs 210,000 plus acquisition incidental costs.
For additional costs for the house including incidental construction costs, outdoor facilities, etc., in other words really "all-in," we can afford/finance a maximum of 610,000. The plot is fully developed.

We are now looking for a smart floor plan that will enable us to build a new house within our means.