Minecraft wiki entry for Building_a_metropolis, associated text: Carpenter Have a carpentry where you can purchase expansions onto your house, as well as have houses built or destroyed. Make the currency to purchase not too cheap, but not too expensive, for example, 5 emeralds for a room 5×9, or whatever you decide. Another example could be 10 emeralds for a 12×12 garage with a fully openable door with redstone. Or you can do other things like making the price cheaper, if they give the carpenter some items to build with, if not free, if all needed items are given.