The new staircase links the front and rear of the building. It is lit by a new rooflight. The staircase is deliberately lightweight - of open mesh and delicate metal components, to allow light from the rooflight to filter down as far as the basement. Glass blocks set in the walls help to provide additional light.
The stair is set in an existing stairwell. It rises without touching the walls of the stairwell and is punctuated by half-landings with curved ends. The end stairwell wall has been profiled to a curved shape to match the landings and to produce an illuminated space for the display of posters and artwork. Fluorescent tubes, wrapped in theatre gel to give a coloured light, are set below the landing floor, enclosed in steel mesh. They are designed to cast light on the curved wall.
The stair is formed from a pair of strings - 152 x 89mm universal beams with steel plates welded to them to support the treads. The treads are of 10mm Durbar steel plate turned down at the edges to form a nosing. They are screw-fixed to the brackets through neoprene washers.
The desire to maintain a light and open stair construction conflicted with the needs of disabled people to have solid risers. It has been resolved by making the risers of stainless-steel mesh, set in a stainless-steel frame.
The balustrades are fixed to brackets welded to the universal beams. They support a balustrade of 15mm steel flats and a 20 x 50mm handrail.