Floor plan design single-family house (urban villa) approx. 140m² (3 children's rooms)

I would do without a dressing room.

I would rather do without the 3rd child.

Topic Extension: Why exactly is the house so "small"? Is it due to your budget? Where will the money for an extension come from in 5, 10, or 15 years if you're still paying off the first loan? Or is it due to the building regulations - such as how much of the plot can be built on, etc.? And then the extension has to fit reasonably into the existing floor plan. I would definitely not place the house on the plot now in a way that *maybe* an extension will be possible sometime in the future.

I would rather do without the 3rd child.

That is a personal decision. A dressing room does not necessarily provide more storage space.

Is there any craftsmanship skill available? There are great ideas on Pinterest. Back wall of the closet is also simultaneously the room wall.

Imagine the question: What if there are twins again

Except for artificial insemination, hitting the jackpot twice is extremely rare.

Later extension: What is your opinion here? A house can still grow later on.

Here only upwards. Adding one and a half meters in width to fully utilize the building window, no one does that.

I need about 1.50m of closet space, my wife also 1.50m. Plus another 1m for miscellaneous.

The actually needed closet meters strongly depend on whether a proper staircase leads to the attic - or just a chicken ladder that you don’t want to carry anything up on.

Finger: Was in our shortlist, unfortunately not in our budget.

But actually, that's not a premium brand. The construction method doesn't have inherent cost advantages. So if the budget fits for one and not for the other, then probably apples and pears have been compared in the service descriptions.

... great ideas Back wall cabinet is also at the same time room wall

I consider these "cabinet as wall substitute" ideas to be extremely questionable in terms of noise.

Dressing room - bedroom I see no problem. Between bedroom - children's room or children's room - children's room I also see that as questionable.