Also to do it legally you will have to leave the propane tank outside and run a hose in. That is if you care about the law, and safety, and that sort of thing. Tanks apparently can explode, although I have never heard about it actually happening. Venting is necessary even with an electric setup. Basement brewing is great, especially in the cold months, but you have to get set up enough to leave it all down there. Don't want to be humping up and down the stairs. Also having a brew room where all your equipment is stored is ideal. I am currently building mine, which will also include the keggerator, snooker table and flat screen. More of a man cave with brewing applications. I'm going all electric and scaling up to 10 gallon batches. Electric can add some noticeable up front expense, but the energy usage per batch is reduced. It is quieter, more precision controlled, and you don't have to refill tanks. You can build your own control panel or buy one like Larry has from High Gravity
http://www.highgravitybrew.com/ProductCart/pc/Build-Your-Own-Brewery-c276.htm
Yah, I know. Home brewing is supposed to save you money, right?
If you got the basement space, think about it as building a small kitchen. You will need a sink. A big one if possible. You can also run an additional water line through a filter to fill your kettle. Some cabinets for storage and counter top support. If going electric you will need to run dedicated lines and a GFCI breaker. If you bottle think about a dishwasher dedicated for bottles. Microwave, Tea kettle for heating small amounts, Stir plate for making starters. A refrigerator for beer storage, and another for a fermentation chamber.You may in the future put a kegerator in as well. You will be spending a lot of time down there, so plan it out for the future expansion. Recliner, couch, foosball table, Pachinko, dartbord, TV, stereo. Better have a phone and a computer terminal for using BF. Now with all this going on you need a bathroom, or else it's the stairs again. Don't forget the decor. Football memorabilia, Beer signs, bottle collections........