A large master bath provides ample maneuvering room for two users including one or both using mobility equipment. Multiple entrances allow for both private and guest use, which reduces the need, space and cost for an additional bath in the bedroom area. An out-swing door to the hall eliminates manueverability issues in and out of the bathroom. Double sinks set at two different heights accommodate all users: short (including children), tall and adults including those who have trouble bending. A lower sink with removable base cabinet allows flexibility to accommodate a seated user as needed. A large, curbless shower works for everyone in the house: adults, children, elderly and even pets. Sheet blocking between studs in the shower and around the toilet provides foundational support for bars that can be added later.
Few existing bathrooms include such a generous footprint, so prepare to make modifications to adjacent rooms as well to gain the extra square footage. Multiple floor drains are best, and the installation in combination with a gently-sloped floor is expensive and intensive.
There are many advanced floor systems that make the installation of attractive, leak-proof, curbless shower floors much easier. Due to the lack of a curb, pay close attention to the detailing along wall edges, under doors and at casework to ensure water infiltration is prevented. Also be sure to specify water-resistant materials throughout, similar to most bathroom designs.