Brennan started by gutting the addition, framing one new wall to create a workable rectangle for the bath, and laying a new plywood subfloor. Using chalk, the couple sketched a layout right on the plywood, figuring out where the tub, sink, storage shelf and cabinets would go, as well as an alcove for a shower stall. Then Brennan hung drywall, cut a new doorway, laid tile, and worked alongside a plumber and an electrician to set the fixtures in place.
Shown: The lone existing bath was just 3½ by 7 feet. Plywood laid across the tub provided a place to rest tools.