The invention relates to a method for constructing habitable installations for floating structures, comprising the following steps: lowering a first adapted standard container (3) through at least one vertical prismatic cavity (25) of a carrying structure (2) until it is supported on support brackets (4) of the floor below; securing the first container (3) to said support brackets (4) of the floor below; and, for each subsequent floor, securing a number of subsequent support brackets (4) to the carrying structure (2) on each container (3) already in position; lowering a subsequent container (3) until it is supported on said subsequent support brackets (4); and securing said subsequent container (3) to subsequent support brackets (4) on which it is resting. The invention also includes a habitable installation (1) constructed according to said method, and a container (3) adapted for carrying out said method.