Roles of Z2-odd N=1 multiplets in off-shell dimensional reduction of five-dimensional supergravity

We discuss the dimensional reduction of five-dimensional supergravity compactified on S1/Z2 keeping the N=1 off-shell structure. In particular, we clarify the roles of the Z2-odd N=1 multiplets in such an off-shell dimensional reduction. Their equations of motion provide constraints on the Z2-even multiplets and extract the zero modes from the latter. The procedure can be applied to a wide range of models and performed in a background-independent way. We demonstrate it in some specific models.