Laura, here is that sketch I was talking about. I have planned for the walkway to continue on the 2nd floor, and for the atrium to curve round on itself to form and enclosed volume.
Structural model from the other week, showing my initial ideas for the building form and its structure - building split up into a number of parts, but all connected. Initially I pictured there to be a few fairly small buildings, as though they were small segments of the larger buildings, broken away. Structure; steel framed, largely glazed.