Terraria NPC Housing Comprehensive Guide submitted by Tel.
Note: Despite the fact that we have been sharing our buildings with the NPCs in game for several patches now there still seems to be quite a bit of misinformation floating about the mechanics of NPC housing.
This guide is intended to resolve some of the rumors and bad information using in-game experimentation and screenshots to clarify. This will not tell you how to make a house in the first place – there are plenty of other guides out there for that! Think of this one as troubleshooting for your house and getting NPCS to move in.
House Requirements for NPCs:
In order for an NPC to consider a house a valid home it must have several things.
Solid outer walls. There can be no open sections in the walls to let enemy monsters in.
Backwall. Approximately 32 tiles of solid background wall with no gaps exceeding a square of 4×4 tiles.
An entrance. This can be a door or a wooden platform on the floor and/or ceiling that will allow access to the room.
A comfort item. This can be any one of the following: bed, bench, throne, chair, or toilet.
A “flat” furniture item. This can be any one of the following: tub, table, bookcase, bench, or dresser.
Lighting. The entire room must be lit – it does not matter how many light sources you use to achieve this, however no tiles may be left in darkness.
Acceptable furniture: Pick one “comfort item” from the left and one “flat item” from the right.
Acceptable lighting is also a must. Make sure the light covers all parts of your house.
Requirements for NPCs to spawn:
Guide: Spawns at map creation. Merchant: Must have 50 silver on your person. Nurse: Must have found and used at least one crystal heart. Demolitionist: Must have a bomb or dynamite in your inventory (as of last patch stickybombs and grenades are supposed to work as well) Dryad: Must have killed a boss. Arms Dealer: Must have a firearm in your inventory (Not including space gun). Clothier: Must have defeated Skeletron
Multiplayer Only: Second Merchant: Three players have a combined total of 50g Third Merchant: Five players have a combined total of five platinum. Second Nurse: Three or more players with a combined health of 400
_________________________________________ House Size:
From my own experiments in game (new world with EoC and Skeletron killed in order to activate the Dryad and Clothier) the NPCs seem to require approximately 32 tiles worth of open space in their home.
In the following image the guide’s home has 7×5, or 35 tiles of open space inside. The merchant is equally happy with his 8×4, or 32 tiles of open space. However a smaller home with only 6×4 empty tiles of space was not eligible to attract further NPC spawns. (Note: The patterned edges are simply to make size apparent and have no bearing on the building’s qualifications as a home.) An additional home with a size of 6×5 was also not able to attract an NPC.
From this we can assume that 7×5 and 8×4 are the smallest open spaces that the npcs will accept.
Height and Width:
Further experiments find our minimum width and height of valid NPC housing.
First a building was built with plenty of height but only enough width for a chair and table (three blocks of open floor space). This was not a valid home. The home was then expanded one block at a time until the arms dealer moved in. From this we can judge the minimum acceptable width of a home is six open blocks of floor space.
Next a home was built with plenty of width but a mere three blocks of height. This home failed to attract any NPCs.
However making the house four blocks tall instead of three was enough to convince the nurse to move in.
Thus we can determine that NPCs require a minimum of six blocks of width and four blocks of height. A 6×4 home is still unacceptable however, as it does not meet the minimum requirement for open space inside the home.
We all know that you can make homes for NPCs out of the usual bricks and stone, however did you know that NPCs will now accept pretty much any building block and background that you can place? Prior to patch 1.0.6 dirt walls and dungeon walls were unacceptable however this is no longer the case as long as YOU have placed the walls.
While you cannot use naturally generated caves as your NPC homes, if you take out the background wall in that cave and replace it with identical dirt, it is now valid. The same goes for the dungeon!
Here are some ideas of odd/unusual building materials that many people will swear to you do not work, yet they do!
Glass house with wood wall, dirt house with dirt wall, grass house with dirt wall. Dungeon brick with dungeon wall, jungle grass with brick wall, assorted ores with brick wall (a repeating pattern of iron, silver, gold, demonite, and meteorite ores).
Hellstone brick and ore walls with red brick background, mushroom grass walls with dirt background, and corruption grass walls with dirt background.
Sand walls with brick background, ash walls with dungeon brick background, ebonstone with brick background.
A quick note on dirt walls (184.108.40.206 update):
As of today’s minipatch (220.127.116.11), player placed dirt walls will now “blend” with natural dirt walls however have a slightly different appearance. In the image below the wall in the large square on the left was natural whereas the wall in the smaller square was placed. If you look closely the player placed dirt wall has flecks of dark gray in it, whereas the natural wall is only shades of brown. This makes it easier for us to remember which dirt walls are valid for NPCs.
The screenshots in the section above were taken before this change so the appearance of the placed walls is still the old one.
Windows and Other Holes
Contrary to popular belief you can put windows and other holes in the background wall of your NPCs’ homes. However these must follow strict rules as well – namely that no hole can be more than four tiles tall or wide. So using your hammer to remove backwall you have reached the maximum size hole you can leave once you have removed four tiles in width and four tiles in height.
Notice that this can be fudged slightly. In the following image the leftmost house has the standard 4×4 window. The guide is perfectly happy with this. The center house however no NPC would move into – the window is five blocks tall instead of four. However the last home was perfectly fine, even with that five block tall gap, since I added wooden platforms to make a windowsill. The platform counts as a tile that will fill the gap.
You can also build homes with partially broken background wall if you want it to look slightly dilapidated, however the sections taken out must follow the same rules of no gaps larger than four tiles long or wide.
Unfortunately this also means that we cannot make neat patterns in backwall for our rooms due to the fact that different types of backwall always leave a 1-tile gap between the two types. So a room like the image below, while it looks good, will not work for either a bed or an NPC. You can force the room to work by lowering the ceiling by one tile so that the room is only four blocks tall, but much of the effect is lost in doing it this way.
Platforms are odd. Unlike other objects which we can pass through these will count as tiles for your walls. This is useful, as it means you do not have to put an actual door on a room that has platform access, however it can also be an issue since we like to use those same platforms as shelves. The following room is not a room an NPC will move into, despite the fact that it looks fine, because the platform shelf in the center is (to the NPC at least) no different than a section of brick wall.
This odd behavior can lead to some rather entertaining results however, as apparently the demolitionist thinks that this is a perfectly acceptable home.
Remember: If a room can be accessed by platform you do NOT need a door!
After some thought about platform floors I decided to do some more research – it turns out that NPCs will not, in fact, move into a room with an entirely platform floor; however, a single block of solid flooring is enough. The NPCs appear to need that one block as their place to stand at night and the block must be within two blocks of the furniture.
A Quick Note About Doors
Wooden platforms in the floor or ceiling of a room count as a door. Doors and platforms do not have to be what we would term useful however – as long as they are contained within the room or its walls the NPCs are happy. Don’t ask me how this door is useful:
Some Thoughts About Water
Water is another of those funny substances – you might have to play with it a bit to get the effect you want. In order to get NPCs to move into rooms with water I had to remove water down to about the door level. However once they were in I could flood the room (removed then replaced a block in the ceiling) and they would stay put. After flooding these rooms I built other acceptable housing on the map, however the NPCs show no indication of leaving their watery homes.
That wraps up this very very long guide. If you stuck with it this far through thank you and I hope you found it useful! May your building projects be both practical and good looking!