I have just pruchased a townhome that has a basement that was once finished. It has drywall, a drop ceiling grid (is missing tiles), and electrical (outlets and such). I have had basement electrical inspected and we are good to go, i have also had a mold inspection and there is none present. The basement has no flooring (carpet has been removed) and has a basement smell. Other than ceiling tiles, flooring and paint what else would I need to make this basement liveable? Would I need to install a ventilation system? This was at one time a functional finished basement.
What you need is obviously going to be temporary. Not knowing what you want or needs to be installed, I'll go with the assumption that your looking for some type of wall finish. Fabric would offer you the most latitude. It can be suspended or stapled. Bed sheets and curtains are items that large and inexpensive; some found in thrift/resale shops. Carpeting/rugs can also be used to cover walls. You can find really cheap paneling in building centers and local lumberyards - sometimes as little as $4-$6 each 4x8 panel. You could hang the paneling by drilling a hole at each upper corner, then use sturdy shower curtain hooks or wire to hold the panels to hooks/nails in the rafters. Any of these ideas would leave the basement virtually unharmed and readily de-constructed.
The carpet was probably removed because it was dirty and the concret looked better for the sale, If no mold is present than I doubt it was removed because of a water problem, throw in some carpet and a few cieling tiles and you'll be good. Unless your sayin the drywall isnt finished ie. no mud, than take a class at home depot how to finish drywall (its very easy) paint than do the floors, your all good.
Depending on the region you live in, you should have a dehumidifier running in the basement during the summer months. Make sure to buy one that will drain automatically - you can run the hose to a drain in your basement. This would take care of the normal rise in moisture and therefore prevent the basement from having a musty smell. When finishing the floor, if you prefer carpet, glue it down. If you happen to get water (other than sewage), the carpet can be extracted, dried, and cleaned. Depending on what you plan to use the finished area of the basement for, make sure you have coverage on your insurance policy for water backup or sump pump coverage if you have a sump pump. This is something you can talk to your insurance agent about. The missing ceiling tiles should be easy to replace.
It will need it's own air conditioning if it does not have one now. If it does not have one it would then surprise me if you don't have a mold problem now. The problem with a basement is the moisture you have to deal with because parts of it if not all of it is underground and placing drywall over a block wall will not keep the water out. What does the room feel like when you walk in, damp, humid, heavy odor or dry and dusty? Is the floor full of cracks and cold? There is so much that can be done with any space just knowing what to look for will save you money. Remember if the air smells like mold then it is mold. Don't be fooled by drywall either. It can hide more things wrong than good.
The concrete floor would have to be sealed. A sub-floor installed before carpet or other final flooring. Rip out the drop ceiling (easy cop-out solution for people who suck at hanging/finish rock). Make sure the concrete walls were properly sealed (lack of cause the damp small). I finished off 1/2 of my basement for about $7G's. That includes the surround system, 40 TV, in-wall speaks and recessed lighting. If you have the capital, gut it and do it right. No matter what you do, the smell will remain. If the block is damp, there is no simple cure.