14“Make for yourself an ark of gopher wood; you shall make the ark with rooms, and shall cover it inside and out with pitch. 15“This is how you shall make it: the length of the ark three hundred cubits, its breadth fifty cubits, and its height thirty cubits. 16“You shall make a window for the ark, and finish it to a cubit from the top; and set the door of the ark in the side of it; you shall make it with lower, second, and third decks. Genesis 6:14-16 NASB
Pretty good description of how the Ark was to be constructed.
You can quibble all you want but you're arguing with the text. An argument that is against you.