Abstract: This invention is concerned with a method for erecting a building comprising the steps of locating storey-high relatively thin-walled precast cured concrete panels having substantially L-shaped cross-sections, in a jig corresponding to a floor or portion of a floor of a building, the panels being in opposed and staggered relationship on a suitable base, the base including a channel and the lower edges of the panels being disposed in the channel, and casting a concrete slab or beam on the load-bearing walls thus erected, portions of said slab or beam as cast being disposed on opposite sides of the upper ends of the said panels thereby to lock the panels by the resulting in situ cast concrete slab or beam above them.