Well the player can build frames from scrap so it stands to reason he should be able to make a working door out of strong materials.
However a door is only as strong as the walls around it. Metal doors in labs/prisons/etc. are so strong because the walls to their sides are also extremely strong.
If you just stuck a metal door inside a normal house the walls around it would give way long before the door itself (while still holding for longer than your average wooden house door).
So I’d say having a strong door you can make with scrap and such that’s tougher than the normal ones but nowhere near as much as the current metal doors isn’t that evil an idea.