A rectangular building structure formed entirely of a plurality of similar interlocking building blocks, each block including:
- (a) a longitudinally extending, rectangular, upper surface terminating at one end in a lower stepped end surface;
- (b) a longitudinally extending, rectangular, lower surface terminating at one end in an upper stepped end surface;
- (c) said stepped end surfaces lying in a common horizontal plane and located at opposite ends of the building block;
- (d) a plurality of generally truncated pyramid-shaped recess means formed in the upper rectangular surface and a corresponding number of complementary generally turncated pyramid-shaped lug means formed on the lower rectangular surface, said lug means being aligned vertically with the recess means;
- (e) a single recess formed in the center of the lower stepped end surface and a single lug formed on the center of the upper stepped end surface, said lug and recess each having a truncated pyramid configuration complementary to each other;
- (f) the stepped end surfaces having a square planar configuration with the longitudinal lengths of the stepped end surfaces being equal to each other, and equal to the width of the upper and lower surfaces;
- (g) a first pair of spaced, parallel, vertically extending smooth end surfaces connecting the stepped end surfaces to their respective longitudinally extending rectangular surfaces;
- (h) a second pair of spaced, parallel, vertically extending smooth end faces connecting the upper surface with the upper stepped end surface and connecting the lower surface with the lower stepped end surfaces, respectively;
- (i) a pair of spaced, parallel, vertical, generally smooth side surfaces extending between the upper and lower rectangular surfaces, and between the pairs of spaced end surfaces;
- (j) the upper stepped end surfaces of the blocks being in abutting, overlapping relationship with lower stepped end surfaces of horizontally adjacent blocks with the single lugs of the upper stepped end surfaces being interlockingly engaged in the single recesses of the overlapped lower stepped end surfaces, with the lower rectangular surfaces being in abutting relationship with the upper rectangular surfaces of lower vertically adjacent blocks with the lug means of the lower surfaces being interlockingly engaged in the complementary recesses of the upper surfaces;
- and with the side surfaces of said horizontally and vertically adjacent blocks forming smooth continuous longitudinally extending wall surfaces, and with the side surfaces of adjacent blocks placed at right angles to each other forming smooth continuous right-angled corner surfaces;
- (k) opening means formed in and extending vertically through each block and communicating with the upper and lower rectangular surfaces, with said opening means of vertically adjacent blocks forming vertically extending passages in the building walls for receiving utility supply lines;
- (l) holes formed in the stepped end surfaces single lugs and recesses and vertically aligned with each other;
- and
- (m) pin means mounted in the aligned recess and lug holes and extending between a pair of vertically adjacent blocks mechanically interconnecting said adjacent blocks.