Also Adam, you don't what to increase the humidity so high that the apartment may grow mold. Keeping the plants you have should not pose that threat. I know some who tried to place there room into a green house and they had a very bad case of mold and mildew. Cost $$$ to remove and a lot of damage. People with tropicals can cause this to happen.
In my cellar, I use plastic to cover the area completely and I know it's not needed with the plants being Sansevieria.
Stush
