a building construction member comprising a rectangular panel with perpendicular flanges extending from one face thereof along opposed edges to form a shallow channel - shaped construction module . when the member is arranged side - by - side with other like members , the abutted flanges of adjacent members become the studs of a wall or the joists of a ceiling . when used to build a wall finished on both sides , the studs of the two sides are interspersed , and may be placed in contact with the panels of the opposite side to reinforce the panels . also disclosed is the blank from which the construction member is fabricated , with particular detail of the gypsum board blank for interior surfaces .