How big is your closet? I can give you an example of how NOT to do this! We moved into our two story with walk out basement last summer. The previous owner converted a half bath in the basement walkout level to a 3/4 by adding a shower. It is squished because my guess is the previous owner didn't want to spend extra $$ to push out an existing wall into the common room. So although not the way I would do it (and certainly not what I would do in a master) we are glad when we need to use the lower level for guests there is a shower there. The original toilet and sink locations remained. Then the shower was tucked to the right of the sink when looking in the door. It may be hard to see from the photos because it is small!

champcamp: small but they did a nice job.

Agreed! They actually picked out finishes that I would select and it functions for what it does. I had a vent fan added after we moved in because there wasn't one and there are no windows but otherwise didn't have to do anything.