It's very difficult to understand your question. It sounds like you should be consulting your architect or builder if you have concerns about this specific plan.

Does "open set back" mean your top floor wider and/or longer than your bottom floor and the floor of upstairs is cantilevered over the outside wall of the bottom floor? If you have a choice, I would not recommend you choose that type of plan. Installing heating duct and plumbing and gutter and even wiring in such plans can be more time consuming and costly and you lose some of the strength of the outside wall as well.

I cannot read all the words on my screen, however, it is pretty obvious that your "lift" closet on one floor is NOT aligned with the wall of the stairs in the way it is on the other floor. I'm speculating that this "lift" is an elevator. You really need to have a conversation with your architect or builder -- perhaps even consider finding a new floor plan and a new architect or builder.

Just glancing at the overall plan, you seem to have a lot of small rooms whereas a more open floor plan -- a great room rather than separate living and dining and kitchen space -- is more livable.

Additionally, your small "common" upstairs area seems to be usable as little more than an unnecessarily large "hallway" space. You might consider other plans and ask questions of the builder from whom you're getting an estimate as to cost.