As title suggests, I think having different stone/metal/wood types actually influence the design, coloration, and pattern of buildings would make a very unique and interesting addition to the building mechanics of the game. Mixing and matching palettes to formulate unique and varied styles for each player would be astounding! Being able to see the different stones used, or woods used, would breathe life into each abode. You already get some of that with weapon and gear crafting, adding the visual element to building would be a great use and addition to the already large assortment of buildable items.
