Open Floors to a common volume


I wish to model a building that has several floors enclosed in a volume that has a large vertical volume that is common to each floor level. We just built one like this but we are thinking we can refine our analysis better. The exterior walls are full of very high end glass and the roof is splattered with skylights. (secondary issues) I am attempting to calculate this building’s energy needs by several methods. Your Honeybee has now joined the chorus. I have enclosed a simplified model to represent the concept. Perhaps it will be helpful in clarifying the challenge.