Abstract: A wall system comprising a plurality of wall panels. Each panel has a vertically extending pilaster formed integrally with one end, defining a vertically open hollow core area of sufficient size for forming a concrete cast-in-situ column for supporting the panel in an upright position. The pilaster further includes an outwardly open groove communicating with the hollow core area. Each panel also has an integrally cast tongue projecting from its other said end, which is received in the groove of an adjoining panel to enclose the hollow core area. A concrete column is cast-in-situ in the hollow core area. Preferably, the pilaster is positioned on a concrete foundation or footing, which includes reinforcement members that project up into the hollow core area such that, when the column is cast, the reinforcement members are embedded in the concrete column. Adjoining panels may be positioned in end-to-end relation, at an angle relative to one another, or stacked.