Terraria DB

Housing

Housing Validity Checker

Walk through every rule the game checks before an NPC will move in — the size limits, the wall rules, the required furniture and the evil-biome limit — and see exactly why a house is being rejected.

Room size

Enter the interior size (the empty space, not counting the wall frame). A house must be at least 60 and fewer than 750 total tiles including its frame.

Interior width
×
Interior height
Total size: 80 tiles (incl. frame)must be 60–749
Fits a minimum room shape≥ 3×10, 4×8, 5×7 or 6×6

Requirements

7/7 met

Toggle off anything your room is missing.

Valid housing
Got a valid house? Use the NPC Happiness Optimizer to pick the biome and neighbors that drop each NPC's shop prices and unlock their Pylon.

How the game decides

When you open the housing menu and pick a room, Terraria scans the enclosed area and checks each rule above in turn. The frame can be solid blocks, platforms, doors, tall gates or trap doors, as long as it forms a continuous seal — an actuated (switched-off) block leaves a gap and breaks it. Liquids inside the room don't affect validity, so water or even lava won't fail a house on their own, though lava will still hurt whoever lives there.

The wall rule trips up the most builds: a freshly-dug room underground is surrounded by natural walls, and none of them count. You have to mine the back wall and re-place a wall of your own across the whole interior. The size rule is measured in total tiles including the one-tile frame, so the smallest legal room is a narrow 3×10 interior.