Abstract: A building block (2) comprising two side panels (6, 8) with at least one open side, the side panels spaced apart by two bridging parts (10, 12), a removable section (17) on at least one bridging part (10, 12), and a pair of recessed or protruding formations (20) on opposite inner faces of the open end of the side panels (6, 8) to enable building blocks to be interconnected. A location device (40) comprising two members (44) spaced apart by cross members (42), where the two members (44) extend beyond the cross members (42) to engage with formations (26) of one or more building blocks (2) is also disclosed. A wall constructed from building blocks (2) and utilising location devices (40) and a method of constructing such a wall are similarly disclosed.

Abstract: A dry wall building system comprises courses of building blocks where the building blocks are joined end to end by keys. Each of the blocks comprising sidewalls, endwalls and at least one vertical cavity or slot, at least one first channel in the upper surfaces of the endwalls and at least one second channel in the lower surfaces of the endwalls, the arrangement and construction being such that when blocks are laid one upon another the channels and the said at least one cavity or slot of the blocks can be aligned to provide an internal network of horizontal and vertical infill passages which can be filled with a settable material to seal joints between the blocks and to provide load bearing support between respective courses of blocks. A method of manufacturing blocks is also disclosed.