What have MORE HP? Wood door/iron door/wall?

[Hesher]

Pls help to understand is here a diffrence in DURABILITY or not. I aslo heared stuff like 3x3 room have more HP than 1x1 room. Its correct?

[Shift]

AFAIK, all doors and walls, provided we're talking about brick/stone walls and doors and not the early game wooden palisades, have the exact same HP. Everything else is cosmetic. A door doesn't have more or less HP than a wall and vice versa, also it doesn't matter the size of a room, one can invade a castle by destroying a single wall or door. What may happen is that a 3x3 room have more pillars and pillar have their own HP, but they won't help much considering you can get in by destroying a single wall and leaving the rest intact.