It depends on where you're going to brew. If you're going to brew in the garage, it's easiest and convenient to have the stand stay set up. I have a pretty small footprint for mine- about 5' long and 3' wide or so. But then there are hoses, carboys, fermenters, some stuff in cabinets, etc. I have tons of stuff in the basement (all my grain, mill fermenters, kegs) and then the brewery in the laundry room. If I had it all in one place, I'd probably easily use a 12'x12' area.
One of my friends (SeaBeeJohn) has an awesome garage set up with his grains on shelfs in rubbermaid bins and the brewery across the garage against the wall. He still can fit cars in there, if he wanted to!