Abstract: A modular structure for suspended floors or roofs which includes a pair of beams 4 supporting a floor slab 5a/5b which is preferably manufactured at ground level and then lifted into position as a modular unit 1. The beams 4 are preferably made of steel and the floor 5a/5b is preferably made of concrete, which may be precast units or may be concrete poured onto profiled steel decking. In either case, the beams 4 and slab 5a/5b are structurally designed to act compositely.

Abstract: A modular building construction system uses either concrete or steel framed wall panels (10) to which are secured roof receiving elements (12, 14) formed by steel girders aligned lengthways close to an upper section of a concrete wall panel (10). An roof structure (16) has pairs of upper and lower projections (18a and 18b) respectively, which are received in corresponding openings in the roof receiving elements (12, 14). With the interengagement of the roof structure (16) and the concrete wall panels (10) one of which is used at each side of the roof structure (16), the building is structurally sound with the walls (10) being held in upright configuration by the roof structure (16) and the roof structure (16) being held up by the concrete wall panels (10). Temporary propping to the wall panels can be removed at this stage.