Furniture Design Hanoi Detachable Sofa by Yuqi Wang Hanoi is a detachable sofa designed for flat packaging. The sofa is assembled in about four minutes without tools, glue or metal parts. Four beech wood pillars are rotated into threaded holes in the wooden base. Upholstered backrests and armrests are then attached to the pillars and fixed with threaded caps at the top of each pillar. Cushions are added last. The packed volume is two fifths of the assembled sofa, which reduces packaging, storage and transport costs. The structure recalls the Tower of Hanoi puzzle.