The method includes a tension element, for example in the form of flat steel, that is placed on the structure or structural part and can be guided around a corner. The flat steel can also wrap as a band around the structure, in which the two ends of the flat steel are either connected to one another or are separately connected to the structure by the end anchors or intersect to produce a clamping connection. The flat steel contracts as a result of a subsequent active and controlled input of heat using a heating element and generates a permanent tensile stress and, correspondingly, a permanent prestress on the structure. The structure, as equipped, has at least one tension element as a shape memory alloy which extends along the outer side of the structure and is connected by one or more end anchors.