A number of the colleges we have been visiting have "substance free" dorms. It's an interesting concept. I'm not an expert on Aristotelian philosophy, but as I understand it, the form of a dorm defines its shape, the substance is the stuff the dorm is made of. Which at first left me puzzled about how one could have a dorm with no substance at all. But I think I have now solved the puzzle.
Obviously, substance free dorms exist in virtual reality--possibly in World of Warcraft, more plausibly in Second Life. There only can you have a building that is all form and no substance.
Which, now that I think of it, also explains how it is possible to have food with no chemicals in it.