Building is a feature which is accessed by the building hammer. To build you just left click with the building hammer equipped and then scroll with your courser. Then click what you want to build. After that a green or red silhouette will appear depending on your placement and materials. Buildings include. Pillars Stair Cases Floors Wall,Windowed walls These items are only for decretive purposes and won`t do much. If a pillar is destroyed by the axe or shark it will destroy anything that is supported by that specific pillar. You can place anything onto the floors including tree crop plots and basically anything. Buildings are a great goal if you want to complete the game. Buildings can be destroyed easily by just destroying the pillar. When raft is on steam all the buildings will receive a complete overhaul and look totally different with replacing the brown thatch to a patter with leaves and sticks.