I have no doubts that something similar will be added later, but I’d like to see additional building materials beyond wood, with varying degrees of strength
First, rocks could yield Gravel in addition to the ores it already produces.
Gravel by itself could be used to create cobblestone, used in the production of various stone structures.
Perhaps smelting cobblestone produces Concrete, for producing concrete structures.
Finally, metal fragments (a lot of them, of course) could be used to create sheet metal, for creating metal structures (for the ultimate in post-apocalyptic feel, it would look like corrugated sheet metal or maybe even a patchwork of metal panels bolted together Fallout style)