I'm actually trying to keep you from using the word "alchemy" to describe him at all. As Rin said, he's not doing that. Alchemy implies that someone is changing one material into another, while Rin was saying though it may look like that's what he's doing, he's really just creating things out of nothing. In eps 11, about 4:44, Rin begins the explaination saying that Shirou doesn't use equivalent exchange (alchemy), but rather he "brought in things that didn't exist before."