A few simple guidelines will make it functional and eye-catching.
1. Go for light-reflecting finishes.
We love this can't-fail combo of traditional white fixtures, a painted medicine cabinet, and shiny chrome hardware with porcelain accents.
2. Don't risk an overflow.
Have a plumber install a backflow-prevention valve on your main drain line to prevent backups into below-grade sinks or tubs.
3. Get rid of humid air.
Extra moisture is the last thing a basement needs. Add a humidistat to your bath's exhaust fan that will automatically turn it on when the air's too damp.
4. Minimize pipe runs.
Here, the sink, tub, and toilet share the same wall, which simplifies plumbing installation and keeps costs down.
5. Handle wastewater properly.
A full, below-grade bath needs a sewage ejector system with a tank and pump. For a half bath, consider a macerating toilet, whose compact tank can handle the sink and john.