I am considering setting up my basement for and entertainment area including a screening area. The only problem is that I only have 7 feet from floor to ceiling joists due to a sunken family room above. Lets start some dialogue to know what all is entailed/has to be considered in digging out the basement. The total area that I would consider digging out is 15 by 20 (part of a much larger area) however there are support poles that line the outside of this area. So the question is what has to be considered to ensure a water tight sunken floor as well as ensuring the structural integrety of the house. I have notice numerous times in the home page where people have excavated to give them head room. One thing that is available is a walkout 10 feet away where malterial can be dumped into a gulley.