Abstract: A structural element with a controllable heat transfer coefficient comprises a frame. A first sheet and a second sheet opposite one another are arranged in the frame. The sheets and the frame have the effect of defining a closed-off volume which is filled with at least one gas. At least one two-dimensional element is arranged between the sheets. An upper intermediate space is formed between the two-dimensional element and the frame vertically upwardly and a lower intermediate space is formed between the two-dimensional element in the frame vertically downwardly. A first cavity is between the first sheet and the two-dimensional element. A second cavity is between the two-dimensional element and the second sheet. The cavities are connected via the upper intermediate space and the lower intermediate space such that a convection flows between the cavities via the intermediate spaces. At least one means arranged in the intermediate spaces controls the convection flow.