This structure is a combination of a dome of revolution and a plate. The low rise dome in the center of an otherwise orthodox flat plate will have shell action at the center of the pane; and plate action along the column lines. This should result in some savings in both steel and concrete. The flat plate elements should be prestressed so that the thrust of the dome can be fully utilized. The reduction in concrete should result in smaller column sizes for multistory buildings. The thickness of the plate at the columns can be made greater than for the ordinary flat plate structure.