To say something is still closed: "It isn't open yet." This can be used for almost anything. Depending on the situation, and on who opens the thing, it can be said in different ways. If you're talking about a shop, you could say "It hasn't opened yet" (because we think of shops as opening themselves). If you're talking about a door/window, you would say "It hasn't been opened yet" (because it is waiting for a person/force to do the action to it).