Ah yes - I had puzzled on why deleting something did not give back resources sometimes, but indeed those were older builds from a saved session and not in that session. I have had some freezes which probably related to thatTechnically, there is a function which would be able to do this, but it is not implemented yet. If you press "F" key (by default) there are a number of options from which to choose, each goes deeper into its menu. If you choose "Build" you can see the "Move" option there as well as "Not Implemented".
You are stuck, for now, with moving items manually and deleting. I should warn you about the deleting part. When you try to delete something that you built in a previous play session there is a chance of a crash. Deleting things as you go in the same play session doesn't seem to cause anything (and gives back resources), but so far I've crashed 4 times from trying to delete something I built previously (which doesn't give back resources). Meaning, build save quit reload delete crash. Don't be afraid to delete, just save often and especially before you start deleting old shit.
Must be an effect of everything being rebuilt in some fashion when a save is loaded since it also resets spawns and similar.
I had forgotten about Build in F menu, pity for time being.