Ezekiel 41:5-9, 11

Then he measured the wall of the temple, six cubits [thick, to accommodate side chambers]; and the width of every side chamber, four cubits, all around the temple on every side. The side chambers were three stories [high], one above another, and thirty chambers in each story; and the side chambers extended to the wall which stood on their inward side all around, so that they would be attached, but not attached to the wall of the temple itself. The side chambers became wider at each successive level as they encompassed the temple. Because the structure surrounding the temple went higher by stages on all sides of the temple, for that reason the width of the temple increased as it went higher; and thus one went up from the lowest story to the highest one by way of the second story. I also saw that the temple (house) had a raised platform all around it; the foundations of the side chambers measured a full rod of six long cubits in height. The thickness of the outer wall of the side chambers was five cubits. But the free space between the side chambers belonging to the temple

The doorways of the side chambers toward the free space were one doorway toward the north and another doorway toward the south; and the width of the free space was five cubits all around.