- Terraforming is independent of buildings on a tile.
- The Sound is likely a building being finished.
While we're asking questions:
What do the Sonar Mapper and Sonar surveyor do?
What benefit do I get from building underground dwellings?
How am I supposed to use the subterranean layer at all?
And how do you make good use of gathered resources? Build a Chemical Plant, process them there, and place buildings next to it that benefit from the bonus?
And how in the name of god are you supposed to make sensible use of diplomacy?
1 the surveyor(it could be the other one I'm not really sure) gives you ability to explore a group of the under ground once per turn for each surveyor you have like scouts pretty much
2 the benefits are 1 you get to house your citizens in place which doesn't get in the way of your surface buildings they only get in the way of your underground buildings of which there are like 1 therefore making them much more space efficient 2 there safe from attack from the surface
3 pretty much what I said above although I think you can harvest some resources underground?.(at least I remember being able to do that I may just be going made here though)
4 pretty much what I've taken to doing is building some like that then putting buildings around it in a circle
5 there isn't really a sensible way to do that personally I don't like the way the diplomacy related things have been changed I mean come on 90 thousand to build an embassy?! REALY?! that just seems stupid to me I also don't really like the pop limit on linguistic centres the limit was fine before but a 1000 limit just seems silly to me.