Originally Posted by joey44
Can we use the metal x-bars to stabilize instead of the back panel?
You should be able to use a metal cross brace. The included back piece is intended to keep the outer casing square. The metal cross-braces will accomplish the same thing.
Are you installing more than one Billy side-by-side? If so, you could connect all the cases and have a single set of cross-braces across the entire group of cases. This would probably leave more of the brick exposed through the book case.