My kids live in a small aparment in Cambridge. It does have a back hall where they found room to install two hooks that hang from the ceiling just inside the door that they can hang their bikes on, and still have room to climb the stairs up to their apartment.

I think it really depends on the layout of your space. In our house, we keep our bikes in the utility room inside the back door opposite the washer drayer. I have thought that if we really needed the floor space for something else, we could hang some hooks on the wall in that area, to get the bikes off the ground.