Multi story buildings are different than standard one floor houses with regards to the layout plan. Layout plans for multi story buildings are drafted with a combination sensitivity between the first floor and other additional stories. When the combination is not secured with acreage not being calculated carefully, the building would not have a proper plan.
For that reason, when you get the floor plan drafted, you should follow the process closely in order to correct any possible errors. You can also get your floor plan checked by another engineer to make sure there is not any errors.