Abstract: A building construction assembly comprises a plurality of vertical columns that cooperate with a plurality of horizontal beams to collectively define a substantially planar frame border of a building. The vertical columns are in the form of upright trusses having a first upstanding member formed with a pair of angle irons. Each of the angle irons has a first projecting leg and a second projecting leg. The first projecting legs extend inwardly relative to the border in spaced parallel relation and the second projecting legs extend in opposite directions along a common line. A support clip is attached to the first upstanding member for supporting an associated horizontal beam in such a position that the outer facing surfaces of the horizontal beam and the first upstanding member defines the substantially planar border. The support clip is defined by a plate for supporting the associated horizontal beam and a load-bearing flange for retaining the horizontal beam.