The title was brew room, but I'm thinking you want to use it for fermenting or aging.
For brewing, think about draining and being able to hose things down along with ventilation and gas/water supply. If you want to ferment or age, you will probably want a separate system for temp than the rest of your house. Keep insulation in mind as well as sealing up drafty air leaks. Is there any exposure to light? If so, block the radiant heat of the sun.
If it were me, I'd use it for aging/storage. I would also use it for fermenting because a basement usually has constant/low temps, and I wouldn't worry about temp control. I use a lot of ale yeasts and make quite good beer fermenting at 72-78 F (loving that WLP001!)