The project illustrated involved the fabricating, erecting and inserting of a new staircase in a private house. the spiral staircase is constructed of a central glass column made from stacking 15mm thick low iron glass discs. The treads are toughened glass bonded to acrylic and span between the glass column and stainless steel curved stringer. The glass column is post tensioned to 3 tonnes by means of a central 16mm diametre stainless rod. This enables it to support the treads. This project involved significant research and testing.