Good morning,
I'm still not completely happy with your ground floor. You have so many small rooms that you no longer have a living room. And because of the entrance on the right, you have quite a long hallway. Would you like to at least swap the WC and the entrance? That way you could save hallway space and make the office or WC bigger.
But I would also recommend not leaving the open space square, because, as I said, you somehow don't have a properly zoned living room.
Unfortunately, I find cost estimation extremely difficult nowadays :confused: