Such kitchenettes were single-room apartments, subdivided from a larger apartment, so they might all share a single bathroom.

"Number Five" refers to a neighbor in one of the other kitchenette apartments. That they are not given a name only further emphasizes the dehumanization of these living conditions, in which they can't even expect hot water.

Why is the city, London in this case, "unreal"? The weather has given it a mystical quality no doubt. But more deeply, the city seems unreal in that it is not realizable, that is comprehensible, to Eliot in the modern sense. In short, he can't make sense of it.