It is previously known to join construction blocks, which comprise two plane major faces and four edge faces, which construction blocks are joined along an edge face of each block, abutting each other, by means of a profile having a web and flanges, and at least the flanges being made of sheet metal. To improve this technique in order to reduce the number of profiles joining the construction blocks and to obtain higher security of the supporting functions against the combination of longitudinal and lateral forces, one web side (7) of the profile (8) is positioned against one edge face of one construction block (1), and a flange (11), which protrudes perpendicularly from the web (7), is mechanically engaged in the major face of the construction block, and the length of this engagement corresponds to at least a portion of the length of the longitudinal extension of the edge face. One edge face of the second construction block (2) is placed adjacent to the other side of the web (7), and a flange (9), which protrudes perpendicularly from the web (7), is mechanically engaged in the same way in the major face (5) of the second construction block (2), the latter major face being on the opposite side of the construction block with respect to the engaged face of the first construction block (1).