Single-family house floor plan - Optimization and assessment

I just asked Google, but I'm not quite clear why a "double switchback" is good for a staircase to the attic? By moving the table, I meant that for Christmas the table is carried into the living room. :)

Because then you have a stairwell where there is room for a well-walkable staircase going up without any significant additional space requirement. You want to build a house, don't plan for guests... If necessary, move the table from one room to another... Give up the fireplace because the architect has to make a new drawing and then ultimately give up the attic conversion. Don't you think you would give up a lot? You don't seem to have any great wishes otherwise, so the few should already find a place in the design.

I need to correct myself a bit: I have looked at your draft again: your knee wall at the top does not work with an additional staircase on the exterior wall. Either you raise your knee wall (at least in the staircase area) or you have to place the staircase in the middle, like e.g. Point150.19 from Danwood (just to be taken as an example)

Carrying the table around? o_O But that means you have a spot in the living room throughout the year that is basically unused, so that when there are more than 5 to 6 people, you can carry a table from the kitchen into the living room? Why not just assign that space directly to a dining/cooking room? That would also allow for more workspace in the kitchen.

I would probably turn the current living/dining room into a kitchen/dining area with direct access to the terrace. Also great for summer days, barbecuing, etc. Or kids playing in the garden who can quickly come into the kitchen and get themselves something to drink.

And the kitchen planned now would become a retreat living room ... where a cozy sofa with a comfortable TV viewing distance fits much better.