When your renovation plans just won't fit into the space available in your current bathroom, you'll need to find a way to expand it -- or carve out space in your home for a whole new bath.
The most economical option is to borrow square footage from nearby areas. Look first to closets and other spaces that adjoin the bathroom's "wet wall" -- the wall that already contains plumbing pipes. It's far less expensive to install fixtures when you can connect them to existing plumbing lines nearby. If you want to expand a master bath, for example, think about keeping the toilet and tub in their original locations and expanding into adjacent space to accommodate the sink (or double sinks) and dressing room. That way you save money and labor by not moving the plumbing fixtures that are the most difficult to move.
Expanding can do only so much good if what you really need is another bathroom. Before concluding that you need to build an addition to your house, however, examine the existing floor plan. You may find underused space that could hold a new bathroom.
Where should you look? Often, a half bath near the family room can take the burden off a one-bath house, as can a secondary bath with a shower stall in the basement. Basement laundry areas are good candidates for conversion because they're already equipped with plumbing. Look, too, at spaces close to the bedrooms.
Another possibility is to divide a large existing bath into two smaller bathrooms. Provide access to one from the master bedroom and access to the second from a hallway. Or, transform a small bedroom into a full bath, then (if necessary) add another bedroom in another area of the house, such as the attic or basement.
Putting a bathroom in an existing space doesn't have to be a major project that puts you into debt for decades, as long as you're careful and practical, and place new fixtures near existing plumbing vents. The main question is where you'll locate the toilet. If the new fixture cannot easily be plumbed into the existing vent stack, the resulting complications can add thousands of dollars to your remodeling budget. In houses of two or more stories, it's most economical to stack the bathrooms directly on top of each other.