A seat assembly for a vehicle seat may have a structural component with multiple reinforcing ribs, a cushion layer, an insert layer which is arranged between the structural component and the cushion layer, at least one component which is secured to the structural component, and at least one securing device. The at least one securing device may secure both the insert part as well as the component to the structural component. A method for assembling such a seat assembly is also described. In one method step, the insert part is secured to the structural component by at least one securing device, and in the same method step or a subsequent method step or a preceding method step the at least one component is secured to the at least one securing device. A vehicle seat have such a seat assembly is also provided.