Abstract: An improved system for forming concrete walls and roofs, such as for one and two story dwellings. A prefabricated frame assembly is formed of a plurality of pheripheral frame sections. Each frame section includes peripheral frame members. The vertical members are J-shaped. The short legs of the J-shaped members support reinforcing rods and the long legs are adapted to support tie rods in the same horizontal plane as the reinforcing rods. Vertical reinforcing rods are secured to and across the first reinforcing rods, thereby to form an open reinforcing network. The frame members provide surfaces to which panel board may be secured. A plurality of the frame sections positioned, as on a slab, are connected to a frame assembly by short tie rods. An array of frame sections and frame assemblies, after paneling has been applied internally, provides a skeleton reinforcing network to which concrete may then be applied to form a reinforced concrete structure.