Systems of cooperative mating building blocks are known. However, there continues to be a need for a system of building blocks which are exceptionally useful for constructing primary or precursor walled, roofed or habitable structures. Further, in the building construction arts, there continues to be a demand for systems of interlocking blocks that are more lightweight and can take on an initial form that is more volumetrically efficient for transportation to the construction site. Moreover, it is particularly desirable for such a system of blocks to enable the rapid construction of larger structural barriers and supports that can also interlock at various angles with respect to each other.