Open staircase realized with laser cut steel monostructure, in “z” shape, laterally fitted to the treads on the wall side. The treads are in wood while the stair railing is characterized by double plate steel posts, six series of brushed stainless steel horizontal bars, and round wooden handrail. In this model, on the external part, on can see the showing part of the steel plates fixing the treads to the same structure.