Floor plan, single-family house, 1.5 stories, solid house. Ideas and comments.

Just throw the fireplace out... Swap the WC and utility room back. Make the loggia half too big and move the stairs forward. The access to the bedroom and office. I'll quickly draw how I mean it...

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The fireplace should stay...

Stairs to the other side - sure, then access to the bathroom and office would be trouble-free, stairs problem solved, only the children's room would no longer be accessible

just as an idea for relaxation.. no idea where how when the fireplace fits in there now.

... This is definitely how the staircase should work, because even in the second attempt by the OP with the omission of the loggia, the staircase does not work.

I have to disagree there. The design without the loggia was built that way – I even took another look at it. 3m long and 1.4m wide L-shaped staircase...

There are also stairs in the chicken coop... what I want to say is: don’t make the stairs too steep, especially if you are still planning freely, that is unnecessary. I don’t like any design here (not even mine). Yours don’t even work... 70 cm hallway to the living room, under 1 m for 88.5 doors, etc. etc. Why don’t you have a house provider draw something for you... they often aren’t that great either but maybe you’ll get lucky. Alternatively, take some money in hand and hire a planner.