Interior Space and Exhibition Design Scala Stair by Despina Souhlas Our goal was to design a stair that would be open but would also de-emphasize the lower ceiling height on the upper level. The treads are open loops for the lower run which stretch upward to form a tunnel to walk through from the landing to the upper floor. The tunnel forms a gateway to the upper level, this constrained tunnel space also allows the consequent room to appear larger and lends it more importance.