I think I've encountered a bug where only three construction materials are listed in the choices of what to build things from. Since acquiring gold, wood is no longer shown in the menu, and this applies to tables, walls, racks, doors, everything. It's quite a problem.
The problem is that materials only show up in the build menu if you have some of them. So if you run out of wood you can no longer build things out of wood until you chop down some trees.
I reloaded the save just now and noticed that the last wood had been taken from just under my nose, so that's exactly it. Thanks though, I was getting a little antsy about it.