Ezekiel 41:6-7

NHEB(i) 6 The side-rooms were in three stories, one over another, thirty in each story. And there were offsets all around the wall to serve as supports for the side-rooms, so that the supports were not supported by the wall of the house. 7 And the side-rooms were broader as they encompassed the house at each successive story, for the structure encompassing the house went upward all around the house. Therefore the breadth of the house increased as it went up, and so one went up from the lowest story to the highest by the way of the middle room.