Abstract: A bathroom floor module is used in conjunction with a fully or partially curbless, handicapped-accessible, waterproof shower module. The bathroom floor module defines one or more drain apertures to mate with a bathroom floor drain. The bathroom floor module and shower module mate to define a contiguous surface over which a bathroom floor and/or wall tile can be applied to create a transition between the bathroom floor and shower over which a wheelchair can be easily rolled. Installation of the handicapped accessible shower comprises installing the shower module, by adhering the bathroom floor module on the bathroom floor, placing an edge of the bathroom floor module in registry with an edge of the shower module, sealing the joint formed between the edges of the shower and bathroom modules, and installing a finishing surface material over the floor and sidewalls of the shower module, and over the bathroom floor module and threshold.