Abstract: Modular tenon and slot mortise building blocks include, for each building block: (a) hollow rectangular parallelepiped center block, (b) an outer siding member, (c) a first tenon member sandwiched between the center block and the siding member, (d) an inner facing member, and (e) a second tenon member sandwiched between the center block and the facing member. The tenon members are parallel and mounted to longitudinal sides of the center block. The tenon members are positioned and of a length so as to extend longitudinally of a first end of the center block by a first distance and so as to form mortised first and second recesses having a first depth behind the first and second tenon members, respectively, between the siding member and the center block and between the facing member and the center block. The first distance is substantially equal to the first depth.

Abstract: Modular tenon and slot mortise building blocks include, for each building block: (a) hollow rectangular parallelepiped center block, (b) an outer siding member, (c) a first tenon member sandwiched between the center block and the siding member, (d) an inner facing member, and (e) a second tenon member sandwiched between the center block and the facing member. The tenon members are parallel and mounted to longitudinal sides of the center block. The tenon members are positioned and of a length so as to extend longitudinally of a first end of the center block by a first distance and so as to form mortised first and second recesses having a first depth behind the first and second tenon members, respectively, between the siding member and the center block and between the facing member and the center block. The first distance is substantially equal to the first depth.