User blog comment:Mathmagician/Patch 1.1 - Testing NPC Housing/@comment-4694163-20111220065225

Inactive stone can be used to replace doors. I read this post and then did a little testing myself with the housing I already had. I use 3x1 high active stones to create doors, with a pressure plate on the outside so I can get in, and npcs can't get out. So I deactivated the stone 'doors' and they were still suitable. However, npcs had a preference for the rooms that did have the stone doors still active, so they tried to escape to those when given the room with inactive. On another note about this, I had no opening at all and the housing is still both suitable and npc valid. I have screenshots to post as well if wanted.

And to point, for those questioning suitability when in regard to Corruption - It will say that the housing is corrupt if the invalidity is caused in any part by corruption.