Methods and apparatus for creating a shower or bath enclosure, in which, given a predetermined area in which to create the shower or bath, a given prefabricated water proof bath or shower floor module is too small to occupy the entire available enclosure space. The apparatus includes the use of one or more additional enclosure components, such as one or more shower benches, to occupy a space between an edge or edges of the floor module and the exterior boundary(ies) of the enclosure space.