I'm not seeing any placeable rooms, sections of rooms, buildings or areas of any kind. Do we really have to scan through that entire resource list and piece together everything? (New Room -> New Spawn -> Big ass folder) Merely trying to get a floor together appears difficult so far!, let alone a whole room.
Maybe I'm doing it the hard way... The wiki wasn't much help. And so far there's nothing intuitive to go on.
Everything else seems to be in the placeable tree, except no area/room pieces.