The staircase poses the problem: a vertical space with only one level of access.

The Cocoon Stair generates a secondary platform. Half of the existing staircase splits upward to meet the new platform. This splitting is an indication of how the two planes - the first being the landing of the stair, the second being the new platform - are related to each other. While they originate as one, they culminate as two distinct identities. This new plane is an inherently private one. The balustrade begins as a railing and ends as a cocoon. In the same way, it also begins in a public plane and proceeds towards a private one.