The staircase is set in a well that rises to the restored roof lantern, exposing the original structure and allowing the height and volume of the original space to be seen, while letting daylight into the stairwell and entrance foyer.
The stairwell is a solid enclosure of timber studwork lined with plasterboard and skim, which splays out to one side at the base of the staircase.
The walls are painted white and the entrance floor is laid with off-white ceramic tiles.
In contrast, the staircase is formed of dark-grey treads and risers of 10mm steel plate, welded, ground smooth and spray-painted with micaceous iron oxide. The whole of the adjacent wall to one side of the staircase is clad with a 10mm steel-plate wall panel, which rises to 1,800mm above the landing.
The handrail is set in a diagonal slot formed in the wall panel, supported by a 190 x 90mm PFC set behind it. It is a 32mm-diameter steel tube, which is welded to the lower edge of the diagonal slot.
The steel-plate panel is bolted and cleated to steel columns set within the wall thickness.
The stair risers and treads are welded at one side to sloping 10mm steel-plate stringers, profiled to fit their serrated shape, and on the other side to the steel-plate panel. The lowest tread is a wide concrete plinth covered with ceramic tiles to match the entrance floor.