Housing
Housing Validity Checker
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.
Requirements
7/7 metToggle off anything your room is missing.
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.