Please provide tips for designing the ground floor plan

As said, done that. Better?

Definitely better in terms of the basic layout and the width of the walkways. Two things stand out to me: - The cloakroom can only be a small wall-mounted closet at the marked location; with 2 adults + 2 children you need quite a bit of storage space for jackets and shoes for different weather conditions, the space under the stairs will probably have to accommodate that. - The utility room will presumably also be used for washing the laundry of all 4 residents? Then I would reconsider the trapped location behind the pantry. Mentally walk the route in your floor plan with a heavy laundry basket in hand from the bedrooms down the stairs, around the stairs, through the pantry door and the utility room door. You could save yourselves a dryer because on the way back it will dry by itself. Maybe with a more space-saving stair design a direct access to the utility room could be created, ideally near the foot of the stairs.

why haven't you turned the kitchen island yet? 70cm is simply too little, it doesn't look good and only one person can get through at a time.

Best regards
Sabine

Precisely for that reason the square floor plan.

Square because of the house axis? - I'm at a loss (?)

The longitudinal axis of the house must be oriented southwest. I definitely want to enter the house from the street side (here east) and have the garden on the west side, as this is the larger green area.

Exactly according to your aforementioned wishes, it would be more logical to give the house a real axis with a rectangular floor plan, which with less house depth would also allow for more garden depth.

Square because of house axis? - I’m at a loss (?)

According to your aforementioned wishes, it would be more logical to give the house with a rectangular floor plan an actual house axis, which with less house depth would also allow for more garden depth.

Please show me how you mean that.

Development plan/restrictions ... Orientation: southern longitudinal axis ...

...The longitudinal axis of the house must be oriented southwest...

A southwest axis? Does that exist? An axis is a straight line running from one cardinal direction to the opposite. Do you mean north-south? Or southwest-northeast?

Typo: East-West direction as the arrow direction