The present disclosure relates to a self-supporting element (1) for the construction of structures, comprising a first and a second side wall (2, 3) wherein at least one between the first and the second side wall (2, 3) is made of cementitious material. The first and the second side wall (2, 3) are positioned in a predetermined positional relationship and are separated from each other by an air volume (4). According to the invention, the element (1) comprises at least one dividing partition (5), placed between the first and the second side wall (2, 3). The dividing partition (5) has a curved profile at least partially doubled and is configured to mitigate the thermal convection within the air volume (4). The present invention further relates to the method of manufacturing the element (1).