So far there has never been a chance to change any non-pet artifacts, I suppose that is because the pets are the most popular of the evolving buildings...
Hold on to your artifacts, even though right now it seems unlikely to happen. If people keep asking over and over for the same thing one day it may happen, Inno has broken down before and done things that they have promised never to do, but it may take a couple years to happen (like the Teleport Spell)