Abstract: A building structure and a method of constructing a wall utilizing the building structure, for the construction of concrete buildings in a simplified manner. Each building structure unit includes a pair of exterior panels of cardboard sandwiching an insulating foam panel, or sandwiching two foam panels which in turn sandwich another cardboard panel. The various panels are glued together, and tabs extend from the exterior panels along the bottom of the structure, and along one side of the structure. A number of the structures are stood in place so that they extend vertically, with the tab portions along their bottoms attached to the building base, and the structures all arranged side by side in interlocking engagement to provide a continuous self-supporting wall structure providing a horizontally impenetrable barrier.