Newly built single-family house approx. 220 sqm, 2nd design city villa

Ground floor better

2 dining areas
3 seats

But I find the children's rooms too small for that
The parents' bathroom as well
You have a larger parental sleeping area than 2 children have for sleeping, doing homework, hobbies, and meeting friends.

Give the children's rooms a sleeping gallery
I would remove one seating area and possibly put one upstairs
No one sits relaxed in front of the fireplace when the TV is running next door

Have you ever written anything about your budget somewhere? If I look at the exterior of your house, you will probably come to over 600k just for the house...

It may be that money doesn't matter to you... Then it's fine. Otherwise, you might have to plan more budget-oriented.

Ground floor better

2 dining places
3 seats

But I find the children's rooms too small
The parents' bathroom as well
You have a larger parents' area for sleeping than 2 children have for sleeping, doing homework, hobbies, and meeting friends.

Treat the children's rooms to a sleep gallery
I would remove a seating area and maybe put one upstairs
No one relaxes sitting in front of the fireplace when the TV is running next door

The children's rooms are >15 sqm, I don't find that too small. Plus a kids' bathroom with a bathtub. As I said, personally I would have removed one of the two bathtubs upstairs. But maybe people like bathing

In relation to the house, they seem too small to me. With 140 sqm, 1 bathroom, and 14 sqm bedroom, it would look different. The children's bathroom is used less than the children's rooms themselves.

we also have a children's room in the northwest. The bedroom and 2 children's rooms are in the south.

The children's rooms have >15sqm, I do not find that too small.

I agree. Our bedroom is only 15.5sqm and is comfortably big. I consider a children's room of that size big.

Plus kids' bathroom with bathtub. As I said, personally I would have removed one of the bathtubs upstairs. But maybe people like to bathe.

I think the idea of 2 bathtubs is good. I also wouldn't want my daughter to always walk through our bedroom just to take a bath.

Either a main bathroom for everyone, or a bathtub in every bathroom. I just find that fair.

The house is also unnecessarily big. If you reasonably reduce it to 190 m², you still don't have any real loss of space.