Regardless of what you are using your basement for, be it a play room, home theater, spare bedroom or a family room, a bathroom will improve it. This project will require special applications you will use in no other home improvement project.
Install plumbing from the location of the new bathroom to the nearest water supply lines. For the toilet itself you will need only a cold water line, but plumb in hot and cold water as you will need both if installing a sink or shower. Tie the new lines into the existing lines by inserting a tee fitting. (Be certain the water is turned off before cutting into the lines.) The new pipes need to end at the location of the sink. At this point you will install another tee fitting to bring the cold water line to the toilet. At the end of all three of these lines install water shut off valves. These will make any future maintenance or modifications much easier to accomplish.
Locate the nearest drain line to the new bathroom area and install a tee fitting. The new drain line needs to be routed by the shortest possible route to the upflush toilet. The upflush toilet will include an electric pump to remove the waste water. This pump will also be used to remove the waste water from the sink and shower as well. You will need to install drain lines from the sink and shower to the toilet so the water can be removed through the main drain line. These drain lines can be concealed in walls, beneath a raised floor or run along the baseboards. Make certain all connections and joints are secure and watertight.
Place the upflush toilet in place. There are many types of upflush toilets. Some appear as normal toilets with the pumping unit and tanks concealed behind a wall. Others are flat containers with the toilet sitting atop it while still others are large stand alone units which appear as an oversized toilet. Regardless of the type you have selected, the plumbing will be basically the same. Connect the main drain line to the outlet port on the pumping unit. Securely attach the drain lines from the sink and shower to the proper inlet ports. Some pumping stations are large enough they have additional inlet ports for washing machines. Select the proper size unit for your application and needs.
Make all electrical connections for the pumping unit. Again, depending on the model of toilet you have selected, the pump may be hard-wired or may need a simple 110v outlet for power. All outlets in the bathroom, both for the pump and any other appliance must be a GFCI device. Depending on the codes in your area it may be required for a licensed electrical contractor to make these connections. If performing the work yourself, be certain all power is turned off prior to beginning any installation or modification.