一个房屋必须拥有至少一个光源, 桌子, 以及椅子. 以下列出的物品均可满足该条件。
A House is considered corrupted based on its "Corruption rating," which calculates all tiles in a 45-block "radius" around the house; a house's Corruption rating must be 250 or less. This is about half the blocks in the radius.
- Each tile of Ebonstone, Ebonsand, and Corrupted vines/plants increases a House's Corruption rating by 1
- Each tile of Hallowed grass, Pearlsand, and Hallowed vines/plants reduces the rating by 1.
- Each Sunflower reduces a House's Corruption Rating by 5.
- 25 Dirt Block for floor, wall and ceiling.
- 32 Dirt Wall (8 Dirt Block) for background wall.
- Wooden Door (6 Wood). Can be replaced with one Wood Platform.
- Wooden Chair (4 Wood).
- Wooden Table (8 Wood) or Work Bench (10 Wood).
- Torch (1 Wood, 1 Gel, results 3).
Summary raw materials:
- Houses may be attached together and share common walls, floors, ceilings, and doors.
- If a House with an assigned NPC is destroyed or any of its requirements are invalidated, the NPC will wander the area until a valid House becomes available again. If killed, the NPC will respawn once a valid house is restored.
- An NPC will not spawn within its House if that House is on the visible screen at the time, and may walk around the area outside instead. Quitting and restarting in single-player mode will place the NPC in its house. At night, NPCs will be automatically placed inside their Houses if the player travels several screens away, or if the player uses a Magic Mirror or Teleporter.
- In single-player, a total of 19 NPCs (20 during the Christmas season) will eventually become available to a player in an ordinary biome who fully advances through the game. It may be worth building a structure containing 19 rooms (or 20 if during the Christmas season) that meet the House requirements when planning a headquarters. The Truffle is an additional 20th NPC (or 21st, if during the Christmas season), but must be in a surface mushroom biome, and will likely need to be housed separately from the player's main structure.
- The side, top, and bottom of the world do NOT count as walls.
- If a stone wall has been converted into Pearlstone Wall, the House will become invalid.
- If building a house at a world's original spawn point, it is best to not place any foreground objects or blocks where characters appear. This will remove the object(s) and place them in the new player's inventory.
- You can replace doors with platforms of any kind if you have 3 where a door should be. Good if you have large rooms or hallways that you want to have NPCs in, or if you hate the sound of NPCs opening and closing doors constantly.
- Placing a light source in a Living Tree room or Floating Island structure will cause it to become suitable housing, unless you have removed its furniture.
- If you wish to prevent NPCs from wandering around, place a torch on the ground on each side of the door (it does not necessarily have to be on the ground since 1.2). It will not only count as a light source but also prevent the NPC from leaving. Keep in mind this will also complicate opening the door for the player, as you will need to face away from the door to open it or right-click the torch and re-place it when you want to enter. Wooden Beams and Platforms can work just as well.
- You can also use the Green, Brown, Blue, Grey and Lihzahrd pressure plate to prevent the NPC from leaving the house, because those pressure plates activate only when players step on them.
- 220.127.116.11: Living Leaf Walls can now be used as a background for houses.
- 18.104.22.168: Opening doors will once again cause a room to be unsuitable, but only if two doors are opened into the same room. (Depends on size of room)
- 1.2: Fixed a bug that would cause a suitable house to be unsuitable.
- 1.1: There is now a built in interface for checking if a house is valid for being moved into and designation the specific house for the specific NPC.
- 1.0.6: Requirements modified; may now use a bed, toilet, throne or bench instead of a chair, and may use a dresser, bathtub or bookcase instead of a table or workbench.