The upper floor is very solid, that looks good imo. Downstairs, the living area will probably be very tight. I don't think you can fit kitchen, table, and sofa on 8m in that form. I'm with our previous speakers on this. We have a wall length of 9m in the living area and that's just barely enough. One meter less and it already gets very tight. Not to mention the distance to the TV. I've recommended this many times here, print out the floor plan and your planned/current furniture to scale and try to puzzle them onto the floor plan. Then you can see very well if it works out. It's also a nice activity to imagine it together.