So the stairs turn out to be a large design element in the space. The stair is located in the back corner of each building and has 69 risers from the cellar to the roof. The stairs were fabricated out of steel with a monostringer (one support down the middle). The steel is extremely heavy and thick. There is a landing between each floor with a large window. The stairs are quite open and there is a lot of light that comes from the various floors.
The monostringers are bolted to the large triple wood members as they meet the floor joists and at the landings. Steel plates were then weleded to the monostringers to create steps (treads). Railings were then welded to the steel plates and to posts at each landing and floor. The entire steel stair structure was painted. I was leaning towards high gloss white - but with the super white walls and ceilings, we opted for grey. Finally 1-1/2" oak treads were attached to the steel plates (the metal fabricator prepped the steel plates with predrilled holes) - for the final result.