That's interesting. In biblical Hebrew גג refers to a top of something, which could be a place for an altar or a place that we might call a roof of a house or palace, but since roofs were probably often open spaces there could be herbs grown there. So גג was definitely not what we would call an attic. It's interesting that attic needs the entire phrase, it seems, עליית גג, since גג alone wouldn't quite suffice, and even then it refers to some overhead storage space. Thanks.