Abstract: A preformed building module is disclosed, the module having a roof or top wall and four upright side walls, the latter having stud-like reinforcing elements, the roof, walls and studs being integrally cast of concrete. The modules are adapted to be associated with each other in the construction of a building.There is also disclosed a building structure embodying modules of the kind described above and further embodying facade walls or panels covering one or more of the module side walls and having spaced upright stud elements interleaved with the studs of the side walls, and still further having a roof overhang.