Bathroom wall surprise

[wayne007]

Due to a renovation after a water leak, decided to remove all the the plasterboard on one of the wall only to find out that there is no noggins and the timber use on the outside is only 1x1, and they have put plasterboards in the middle of it.

What can I do as I what to use elements of tile backerboards on it?

 

[He who knows]

Is that all of the wall, or just a section of it? What's on the other side?

Just wondering if tearing it all out and rebuilding from scratch with proper sized studs and noggins might be easiest overall...