Building panel

Claim 1

A rectangular precast panel for use in constructing walls and floors of buildings, which panel is made of a cement-based material and comprises a first and second face that are opposed to each other, a pair of first opposed sides and a pair of second opposed sides, wherein: (a) each first side has a shoulder spaced apart from the second face of the panel, one surface of which shoulder is flush with the first face of the panel and there being a void between a second surface of said shoulder, opposite said one surface, and a plane of the second face of the panel; (b) each second side is shaped to internest with a second side of an identically-shaped panel; (c) the panel further includes a plurality of engaging means embedded in the panel adjacent to each of said first sides, and bores extending from each engaging means to the said second face whereby bolts can be secured in the panels by engagement with said engaging means to hold shuttering against said second face; said panel also including a plurality of securing members each having an arm embedded in the panel and a hook part extending from one of the first sides, said hook part being capable of hooking onto a structural member to engage the panel on the structural member.