I've found out that if you order a con unit to make a building and then, after making the base of it, make the unit repair the building and it skips the terraforming part!
I actually didn't get this all terraforming deal when building structures, because 1) unit takes it time to terraform first and then build the building itself with full efficiency 2) It takes long time for low buildtime units to terraform(ex. con planes) 3) The whole terraforming doesn't help in any way, It just makes buildings not float in the air and I never can build a factory from which units couldn't go outside! + after completing the structure you can restore the ground under it!!
