Floor plan of a family house in an edge location with an open view

Don't know the history, but…

there is (relatively) way too much hallway.
This is due to the entrance/vestibule in front of the house.
You can avoid the hallway window by moving the stairs forward (WC/stairs/office) and placing a window there.

I also don't understand this "new trend" of accessing the door through the countertop. If anything, put the door diagonally in the corner.

The dining area is a bit tight!

What is this 1.5 m strip for in the living area?

You can see through from the street to the terrace here. I would never do it again.

If done frosted, finished.

What is the purpose of this 1.5 m strip in the living area?

That is a terrace deck :) it is pretty and connects ;) I just noticed: the kitchen is super tiny and has hardly any storage or workspace. -> pantry away and/or play Tetris again.

I would also get rid of the pantry and instead plan the storage space properly.

I just noticed: the kitchen is super tiny and has hardly any space for storage or work surfaces. -> Get rid of the pantry and/or play Tetris again.

I would also throw out the pantry and instead plan the storage space properly.

Do you have an idea how?
I find a pantry important. You can store a lot. Simple shelves are enough.
At the moment, I have a similarly sized kitchen and I manage the work surfaces really well. With this layout, I would even have one more tall cabinet.

You can avoid the hallway window by moving the stairs forward (WC/stairs/office) and placing a window there.

The stairs would have to stay where they are now (+/- 50cm). They actually have an impact on the layout upstairs. At the front facing the street, there should be 2 children's rooms of about 4x4m, and at the back facing the garden would be the parents' area.

I also don’t get this "new trend" of having a door through the countertop. For my part, a diagonal door in the corner would do.

Yes... there would also be a sliding door to the terrace deck.

The dining area is a bit tight!

The house could be extended by another 50cm. 3.5 x 4m for the dining table is too small?