sjb007 made some very good points. Create an accurate base plan from the architectural plan and save a copy of that. Post a link to that plan and a few members here will gladly take a look and make suggestions. Include the missing information that sjb007 mentioned.

Concerning the bathroom not allowed to extend onto the balcony: why?
Ask the architect for the reason. If it's because of building codes there's nothing to do about that but if there are technical reasons ask what those are. Maybe with a different design you can still extend the room, if only a little. It probably has to do with weight, drainage points, and most likely that the new outside wall (balcony border) can not be build on a load bearing base.