Abstract: A modular, pre-insulated and pre-finished structural building block comprised of structural and insulating elements, fastening rods for the attachment of building blocks to one another and to other wall components, and facing elements of selected materials and finishes affixed to the building block. The building block incorporates into its construction common and varying sizes, shapes, and configurations that fasten to one another and to other wall components in the assembly of a wall, and may be unfastened from each other in the disassembly of a wall without damage to the building blocks or wall components. The building block further incorporates into its construction fastening components that attach to fastening couplings in anchor plates, top plates, door and window frames, window sills, and headers. Additionally, the building block incorporates into its construction electrical boxes and wiring conduits attached to and within selected building blocks.