Abstract: A footing box has notches for receiving an end of grooved grade beams. The end of each beam includes an aperture for receiving a reinforcing rod extending lengthwise from a grooved column supported on the ends of the beams in the footing box, to enable the grade beams and column to be unified when grout is poured into the footing box. Grooved roof beams are supported at their ends by the column and connected to the column by a reinforcing rod extending through an aperture in the end of each roof beam. Wall panels are positioned in the grooves of the column and the beams.