Floor plan design single-family house 150 sqm - tips for improvement?

What am I supposed to explain there???

You need to be more precise about what you like and don’t like about your floor plan. What is a "must-have" and what can be different? Otherwise, you can just keep your last floor plan as it is and be done with it. So what bothers you about it? An open staircase would appeal to you – also so that the hallway doesn’t become so dominant. At least, that’s how I understood it. For me, the last suggestion was actually much more about the size and furnishing possibilities of the living room. But it seems you prefer your current floor plan. The "parents’ area" also forms a unit with a separate door. Is that good now, or do you not like the bedroom-bathroom-dressing room arrangement that way? And so on and so forth. Tell me a bit, come on, come on. Just always remember what it will cost you. That’s motivating.

Doesn't do it. Can't do it. Man.

Optimization is successful when you set out with the willingness to change everything, and the result coincidentally closely resembles the original model - not when you specify as a goal that only little should change.

Just a little pocket Confucius saying

Tell me a bit, come on, come on. Just always remember what it will cost you. That motivates.

[*]Small guest WC on the ground floor
[*]Bathroom 10-12sqm with open shower without glass wall and T-divider
[*]Bedroom with the current dimensions in my draft would be enough
[*]Dressing room for two 1 - 1.50 elements (min. 2m - max. 3m total for wardrobe elements)
[*]Utility room on the ground floor, if possible with outside access from the carport (but not a must)
[*]If possible already a small covered area for smokers (my wife & guests) but absolutely not a must!
[*]Counter for 3 people where you can sit in the kitchen area
[*]Kitchen U-shape or two rows
[*]Exterior view of the house from the front (entrance area) with a few windows as usual 4 or more + front door unit and not like in a draft only two windows!

Now I am curious!

Your wishes in the room program don't really match the house size. As a result, you have too little space for living/dining.

Maybe my comments are a bit provocative.

[*]Small guest WC on the ground floor

Ok

[*]Bathroom 10-12 sqm with open shower without glass wall and T-divider

Can also be smaller. Size isn't everything.

[*]Bedroom with the current dimensions in my design would be sufficient

Ok

[*]Dressing room for two 1 - 1.50 elements (min. 2m - max. 3m total for closet elements)

Why a dressing room? That's not much closet space. You won't find a floor plan with your planned house size and a dressing room.

[*]Utility room on the ground floor, if possible with external access from the carport (but not a must)

Why on the ground floor? It doesn't hurt to have the fuse box and so on upstairs.

[*]If possible, already a small covered area for smokers (my wife & guests). But by no means a must!

I can understand that. I wouldn’t want that in front of the bedroom.

[*]Counter for 3 people where one can sit in the kitchen area

Why, the dining table is just a few centimeters away?

[*]Kitchen U-shape or two rows

I would plan the building services upstairs.
Dressing room out. Make the bedroom a bit bigger.
Bathroom approx. 10 sqm.
Pantry later for the washing machine.
Kitchen two rows without counter.

Now I am curious!

Which of your mandatory points does my proposal not meet if you turn the pantry into the utility room? The same applies to your current floor plan. Do you understand the problem? Your wishes are personally too much for the ground floor for me. Although you are building over 12m house width, the rooms are all tiny (except for your bathroom). You always get the feeling of living in a 60m² apartment. Is that what you want?