If there was an Item we could buy for a few dollars that would let us swap out the materials on an existing building, I'd snap that up in a heartbeat. I'd really rather not tear down the mill just to change it's appearance, and I'm sure theres other buildings that people have second thoughts on all over the world.
Could be rather easy to put in, just give us a little item, let us right click on the building with it to pop up a menu. The menu could show Primary, Secondary, Tertiary, etc. material types, let us pick one from a dropdown with a in-world preview, and then let us apply to change it. I'd redo my whole village with these if given the chance. (Except the Basalt Tower.) Hopefully it'd be a good income source for the game as well.
(Side note, if I were swapping materials on the windmill, Porphyry, Basalt, Leather Cloth, and Cherry Wood would be my choices.
