Our targeted floor plan - please provide assessments

Unfortunately, the plans are a) hard to read and b) a few measurements would be helpful. There is also no site plan of the property, so you cannot tell how the rooms would be situated (east, west, south, north, etc.)

One could also put the study (possibly with a sofa bed) on the ground floor and use this small room upstairs more as a general dressing room, a laundry room, or a small reading room with a sofa bed for guests or something like that.

In general, the entrance does not have to be "set back" but could be normal. The guest bathroom could then be moved next to the guest room, allowing the entrance area to be more spacious with wardrobe cabinets and possibly a vacuum cleaner/mop closet. And you could omit the storage room.

The kitchen... unfortunately, measurements are really missing, but it doesn’t look very great either. The drawn-in dining table looks like it is in the door and entrance area of the kitchen, and there doesn’t seem to be much more space.

Right... A storage room on the ground floor is probably a good idea after all.

In the hallway, apart from under the stairs, I don't see any possibility to put a wardrobe here. Under the stairs won't be sufficient, will it? A shoe cabinet would also have to go somewhere.

I already wrote before, generally I have nothing against using the office as a guest room as well. But then we would also have to put everything in that the guests need, and that includes at least a lying surface for 2 people... And then my shelf, desk, chair...?

Sure, not everything depends on the kitchen table. But it would be important to me, and then the kitchen might have to be planned larger.

Well... All in all, probably too small because of the kitchen and hallway and office upstairs as well?

What are the exterior dimensions of the last floor plan? Maybe it’s not too small, but rather divided incorrectly.

I have a 12 sqm study with a desk surface along the entire 3m wall, resting on shelves on each side. Additionally, there is a very good sofa bed in the room that has a lying surface of 160x210 cm when extended. It is a sofa suitable for permanent sleepers and my guests are very satisfied. There is also a separate niche in the room for the set-up ironing board . It is my home office and very practical.

True... A storage room on the ground floor is probably a good idea after all.

In the hallway, apart from under the stairs, I don't see any possibility to set up a wardrobe here. Under the stairs won’t be sufficient, right? The shoe cabinet would also have to go somewhere.
....?

"Under the stairs" is not possible in the basement

Right, completely suppressed...

The setup of your home office sounds very good.... With clever furniture arrangement, quite a bit can probably be done.

but this hallway... That simply won't be enough space-wise, right? I'm not a fan of cluttering everything up. But at least some proper coat hooks and a shoe cabinet had to find room, otherwise we'd be worse off space-wise than we are now...

I looked at catalog designs from both providers, and apart from the clearly different price range, these hallway areas are always between 10-15 square meters. That really can't be enough for any family. Do you think these floor plans are offered with the knowledge that they're not really sufficient and people will just upgrade anyway?

What does your plot / building area even look like? Without knowing that, you can’t judge a floor plan! Maybe a rather rectangular floor plan would work instead of a square one. You want to build a 150m2 house plus a basement, and you can’t get a reasonable seating area in the kitchen on the ground floor?! Neither floor plan matches your wishes. Catalog floor plans suit many people, but not everyone, and above all, in many cases, they don’t fit the plot without being heavily and expensively modified.