Optimization of floor plan for detached single-family house 155 sqm

But you don’t necessarily need to cross-ventilate there, since the bedroom does not face south. Also, unlike the children's rooms, you don’t spend much time in the bedroom, so you can keep the west window closed on sunny days.

Sounds convincing.

Definitely! Plan the wall so that the wardrobe and the fictional closet behind the office door can have a depth of 60 cm.
Think about where the TV and sofa should be placed. In my opinion, the large floor-to-ceiling window in the sofa area should rather face west. The terrace door opposite the entrance door of the open-plan room.
A dormer window is also suitable in the upper floor hallway, just like in the dressing room.

We had already considered moving the wall several times. However, the office/guest room is large enough to fit a bed, a desk, and a closet. We will not have a TV, only a projector with a screen (mounted on the ceiling above the floor-to-ceiling window). The sofa should accordingly be placed against the interior wall facing the garden. Since the garden to the west is no longer very large, I liked the large window facing south better.

Yes, you can see that. But yellow bags, beverage crates, and the mop simply don’t fit in there.

We are planning a large storage room by the carport. Also, there is of course the attic with a huge area for things like Christmas decorations.

Here are some examples.

Thanks for the effort. My wife and I went through the different variants, but we didn’t really warm up to any of them. We could also live with the current version. Storage space is of course an issue; the window facing east above the washer/dryer bothers in that regard. I will also try to sketch in furniture myself.

Oops, no controlled residential ventilation? - I didn't even notice that. I would - if I remember correctly, even aiming for EH40 - do it centrally in a new build today. I associate window seats with non-hearing books, do people still have those today?

We actually have KfW 40 without a ventilation system. Everything has already been approved by the energy consultant. A ventilation system would cause around 13,000 € in additional costs.

We actually have KfW 40 without a ventilation system.

Then have a ventilation concept created now (you need it anyway) and see if you can ventilate that often during the day.

We actually have KfW 40 without a ventilation system. It has also already been approved by the energy consultant. A ventilation system would cause approx. €13,000 in additional costs.

I would rather phrase it the other way around: omitting the controlled residential ventilation is compensated with a deceptively low price reduction of €13k. Without controlled residential ventilation, there is no heat recovery, but rather heat loss through shock ventilation – which, in my opinion, perverts the upgrade to EH40 instead of the Building Energy Act. By the way, why do you only address the part of my draft criticism that lies after the comma? Are you too proud a father of this "planning" to engage with it more radically?

I only see one "guest" instead of two home offices,

Only one HO space is needed.

However, the office/guest room is large enough to fit a bed, a desk, and a wardrobe.

I was talking about making it smaller so the hallway isn't cramped.

My wife and I went through the different options but we didn't really warm up to any of them.

That's a pity. I find them all more successful than the original. However, you really don't warm up to the room dimensions.

Why do you actually only address the part of my draft criticism that lies behind the comma? Are you too proud a father of this "plan" to be able to deal with it more radically?

The window seat is my wife's wish and is not up for discussion. In the kitchen, I also consider it practical as a bench in combination with the dining table.