Less is More: Aaron Tang's Wall Stairs

What will the building inspector make of this, the perfect stair for small spaces? Industrial designer Aaron Tang says

"Using simple mechanical hinges and pistons, this inventive staircase easily folds flush up against a wall to expand a lower space and/or to restrict access to an upper floor. The mechanics within the design allow any person to easily open or close the staircase from upstairs or downstairs. Inner pistons help slide the stairs back up swiftly to create a flush wall. The pistons also act as a gradient to lower each step individually after the stairs have been pulled out, creating a gradual, elegant wave-like pattern as the steps individually lock into place."

::Wall Stairs ; be sure to look also at his ::Design process; via ::Architectnophilia