Fuente: WIPO "rice" A variable pitch form for the casting of concrete slabs which become modules of multiple story building structures, the form having an upwardly facing slab casting panel bordered longitudinally by channel shaped beam casting forms integrally connected to the slab casting panel by flexible fillet casting strips. Means are provided for raising and lowering one longitudinal margin of the slab casting panel and the corresponding beam casting form while maintaining the beam casting forms as well as leg casting forms at the corner of the slab in an essentially vertical position. Outboard end forms are provided to match various selected slab pitches or slopes. The beam forms carry pivotal ledge casting forms to provide longitudinal ledges for the support of adjacent modules.