The present disclosure relates to the building industry and in particular to a block for use in automated building construction. In one aspect, the block comprises a generally cuboid body having a top and a base, a length extending between a pair of opposed ends, and a width extending between a pair of opposed sides; the body including a plurality of hollow cores extending from said top to said base, and arranged in a row between said opposed ends; wherein each core has a rectilinear cross-sectional shape; and wherein the thickness of the block between each pair of adjacent cores is at least double the thickness of the block on all other sides of each core, so that the block is divisible into a plurality of substantially identical block portions, each portion including four walls of substantially uniform wall thickness about its core.