I can't imagine brewing as I do right now without my garage and basement. It's not so much a question of having space for a particular activity; temporary space can always be cleared out. It's the STORAGE.
Three primary buckets (which cannot be stacked) and four carboys, bottling bucket, boil pot & HL pot, chiller, all the minor paraphernalia, bins with stocks of malt and adjuncts and (normally) five batches of bottles in inventory takes up quite a bit of room in the basement.
In the garage, MLT, malt grinder setup, burner, & empty bottles take up more space than I'd like.
If we had to seriously downsize our residence, brewing would be on the block, I think....this is just not an activity that lends itself to a small volume of equipment. Although I am always interested to read how apartment brewers or etc. go about dealing with the smaller space.