A structural block assembly having a tensioning system for contributing to the tension load bearing attributes of the structural assembly, the structural assembly comprising: a plurality of structural blocks, each structural block having a first surface, an opposed surface, opposed side surfaces and opposed end surfaces; a plurality of load bearing structural members embedded within each structural block, these members being struts, a protruding end of each embedded member extending from said first surface of the structural block, wherein one or more of the embedded strut members comprises a lengthwise cavity therethrough; a plurality of apertures extending within the structural block from said opposed surface of the structural block, each aperture adapted to engage with a protruding end of an embedded member of an adjacent structural block, the protruding end of each embedded member extending from the first surface by a distance equivalent to the depth of the aperture within the block such that the protruding end of an embedded member of one block engages in an aperture of an adjacent block and is in direct contact with the embedded terminating end of an embedded member of the adjacent block; and wherein the embedded members of the assembled structural blocks form a stacked structure forming a load bearing structural member, wherein the assembly further comprises tensioning means positioned within the lengthwise cavities of the embedded members, wherein the cavities of the embedded members of adjacent structural blocks align to form a lengthwise conduit for receiving therein the tensioning means; wherein the apertures and protruding ends of the embedded members function as locating means for accurately positioning a structural block with respect to an adjacent block during assembly while also contributing to the load bearing attributes of the block under compression; characterized in that each structural block further comprises a compression strut extending in a direction approximately perpendicular between and in contact with a pair of embedded members of the structural block. a plurality of structural blocks, each structural block having a first surface, an opposed surface, opposed side surfaces and opposed end surfaces; a plurality of load bearing structural members embedded within each structural block, these members being struts, a protruding end of each embedded member extending from said first surface of the structural block, wherein one or more of the embedded strut members comprises a lengthwise cavity therethrough; a plurality of apertures extending within the structural block from said opposed surface of the structural block, each aperture adapted to engage with a protruding end of an embedded member of an adjacent structural block, the protruding end of each embedded member extending from the first surface by a distance equivalent to the depth of the aperture within the block such that the protruding end of an embedded member of one block engages in an aperture of an adjacent block and is in direct contact with the embedded terminating end of an embedded member of the adjacent block; and wherein the embedded members of the assembled structural blocks form a stacked structure forming a load bearing structural member, wherein the assembly further comprises tensioning means positioned within the lengthwise cavities of the embedded members, wherein the cavities of the embedded members of adjacent structural blocks align to form a lengthwise conduit for receiving therein the tensioning means; wherein the apertures and protruding ends of the embedded members function as locating means for accurately positioning a structural block with respect to an adjacent block during assembly while also contributing to the load bearing attributes of the block under compression; characterized in that each structural block further comprises a compression strut extending in a direction approximately perpendicular between and in contact with a pair of embedded members of the structural block.