Abstract: A collapsible wall stud and building system which uses the wall stud is disclosed. The collapsible wall stud includes spaced inner and outer channel members that are joined to each other by pivot arms. When the collapsible wall stud is in its fully open position, wall panels can be placed between the inner and outer channel members. As the collapsible wall stud is closed, flange portions of the channel members seat in grooves in the panels thereby joining adjacent panels to form a wall section. The wall sections are placed in floor channels and are capped by top channels to which are secured suitable roof truss elements that form a roof. The collapsible wall stud facilitates the construction of a building by one unskilled in conventional building techniques.