Prefabricated building and kit

A building comprising:

• a plurality of building blocks including a first building block and an adjacent building block arranged in an interconnected and stacked relationship to define a wall structure;
• the first building block including a first end surface, a second end surface, an inner surface extending between the first end surface and the second end surface, an outer surface extending between the first end surface and the second end surface, a first horizontal surface extending between the first end surface and the second end surface, a second horizontal surface extending between the first end surface and the second end surface, and a tab that is substantially coplanar with the second horizontal surface and extends from the second horizontal surface beyond the first end surface;
• the adjacent building block including an adjacent first end surface, an adjacent second end surface, an adjacent inner surface extending between the adjacent first end surface and the adjacent second end surface, an adjacent outer surface extending between the adjacent first end surface and the adjacent second end surface, an adjacent first horizontal surface extending between the adjacent first end surface and the adjacent second end surface, an adjacent second horizontal surface extending between the adjacent first end surface and the adjacent second end surface, and an adjacent tab that is substantially coplanar with the adjacent second horizontal surface and extends from the adjacent second horizontal surface beyond the adjacent first end surface;
• and
• a plurality of vertically extending guide members arranged in a horizontally spaced apart relationship corresponding to a desired wall structure;
• wherein the first end surface abuts the adjacent second end surface and the second horizontal surface is substantially coplanar with the adjacent second horizontal surface, wherein one of the guide members extends through a first vertically extending guide hole in the first building block, and another of the guide members extends through a second vertically extending guide hole in the first building block and through an adjacent vertically extending guide hole in the adjacent building block, and wherein the second vertically extending guide hole is located in the tab of the first building block.