Wall (1; 1') having built-in formwork, comprising: • - two skins (2; 3) which are arranged one (2; 3) opposite the other (3; 2), are substantially parallel and are spaced apart so as to define between them an internal volume to the wall (1; 1'); • - at least one attachment means which is configured to attach these two skins (2; 3) to one another; • - at least one connecting means which is configured to connect this wall (1; 1') having built-in formwork to another similar and juxtaposed wall (1'; 1) having built-in formwork, adopts a retracted configuration and a deployed configuration and comprises a first part, which extends inside the internal volume of this wall (1; 1') having built-in formwork, as well as a second part, which, in the deployed configuration of the at least one connecting means, extends laterally and outwardly relative to this wall (1; 1') having built-in formwork as well as in the extension of the internal volume of this wall (1; 1') having built-in formwork and is intended to extend inside the internal volume of the other wall (1'; 1) having built-in formwork and, in the retracted configuration of the at least one connecting means, extends at least partly inside the internal volume of this wall (1; 1') having built-in formwork; • - at least one mounting system which is configured to mount the at least one connecting means on the at least one attachment means; • - characterized by the fact that the at least one connecting means comprises at least one elastic plate (8; 8') which comprises an immobile part, which is immobile relative to the at least one attachment means, and a movable part, which is movable relative to the immobile part of the at least one elastic plate (8; 8') and can be deformed and regain its shape so that the at least one connecting means can pass from a retracted configuration to a deployed configuration, while the at least one mounting system comprises immobilizing means which are configured to immobilize the immobile part of the at least one elastic plate (8; 8') relative to the at least one attachment means. • - two skins (2; 3) which are arranged one (2; 3) opposite the other (3; 2), are substantially parallel and are spaced apart so as to define between them an internal volume to the wall (1; 1'); • - at least one attachment means which is configured to attach these two skins (2; 3) to one another; • - at least one connecting means which is configured to connect this wall (1; 1') having built-in formwork to another similar and juxtaposed wall (1'; 1) having built-in formwork, adopts a retracted configuration and a deployed configuration and comprises a first part, which extends inside the internal volume of this wall (1; 1') having built-in formwork, as well as a second part, which, in the deployed configuration of the at least one connecting means, extends laterally and outwardly relative to this wall (1; 1') having built-in formwork as well as in the extension of the internal volume of this wall (1; 1') having built-in formwork and is intended to extend inside the internal volume of the other wall (1'; 1) having built-in formwork and, in the retracted configuration of the at least one connecting means, extends at least partly inside the internal volume of this wall (1; 1') having built-in formwork; • - at least one mounting system which is configured to mount the at least one connecting means on the at least one attachment means; • - characterized by the fact that the at least one connecting means comprises at least one elastic plate (8; 8') which comprises an immobile part, which is immobile relative to the at least one attachment means, and a movable part, which is movable relative to the immobile part of the at least one elastic plate (8; 8') and can be deformed and regain its shape so that the at least one connecting means can pass from a retracted configuration to a deployed configuration, while the at least one mounting system comprises immobilizing means which are configured to immobilize the immobile part of the at least one elastic plate (8; 8') relative to the at least one attachment means.