Hi!

In my previous game, I noticed it was impossible to "upgrade" building to some of their "unique" version. 

For exemple, the colonial farm can be evolved in xeno-farm (practical), but then if you want to upgrade one of them in food distribution center, which often make sense, you have to destroy the farm, loosing all bonuses the time you are constructing the new building. That's a bit not practical.

A good way to improve that, IMHO, would be to open a panel when you click on upgrade to show you what are the potential upgrades available for this building and let you choose the one you want.