Prefab adds premade houses, greenhouses, warehouses and barns. When you start up a new world with Prefab, you will be given a basic starting house. This includes a full set of leather armor, stone tools, and basic seeds and crops. To make bigger houses and other structures you must craft them using triple compressed blocks. These are created by filling up a 3×3 crafting with your block of choice. Once you have these you also will need specific ingredients unique to the building you are trying to build. For example, for the brewing/enchanting house you will need both a brewing stand and an enchanting table.