With the right distance set for the IVAR Drawers from the wall (see picture below), the the first part of the closet could be build.
First attaching a pole to one of the beams in the ceiling and to the floor gave us support to create the floating look of the bottom shelf. The self is resting of the floor-panels all the way around, and then the pole is giving it the proper support to not break or tip over. The pole is attached to the floor by using an iron angle and very small screws, that later is painted to cover it up.