Time is money, as they say. And you know what else costs money? Telling your GC to re-frame a wall because you don't like where it is...that costs real money. That's why I always recommend taping out your floor plan to get an initial feel of the space. You need to learn how to read a tape measure, some blue painters tape, and a bit of patience. This is actually one of my favorite things to do because it is the first time you will feel the physical space you are going to create.