Monkeygrinder's Organ
Dodgy geezer swilling vapid lager
I have the materials to start making buildings, but it won't let me craft them. Ffwhy?
You go into the workbench, but don't stand by the bench (like I did). If you walk away from it without exiting the workshop menu you'll be able to see what you're crafting and where you can put it. At the actual bench there's no room so you can't do it.
That's if you've got the same problem as me - it took me a little while to work out.