Adding a bathroom to a basement
As a contractor who has specialized in basement finishing for the past five years we have added many bathrooms to existing basements. A lot of the basements we are in newer subdivisions in Overland Park, Olathe, and Shawnee. The builder will usually stub out a 3″ line for the toilet, a 2″ line for the lavatory, and another 2″ line capped below the slab that will serve as the shower drain.
In some cases the builder will also stub out a vent in order to prevent from having to use an air admittance valve. The problem with AAV”s is that they can go bad over time and leak out sewer gas. They must also be in an accessible location which can sometimes lead to unsightly access panels.
Almost all of the basements we have added bathrooms to have involved using a jackhammer to relocate a portion of the plumbing. In order to get the best use out of your space you may need to rework the plumbing. If this is the case, it is just as easy to use any other 3″ branch that may be located in a different part of the basement. Most of the time we can fully rough in a basement for about $2,000.