Is it possible to make a door be always closed by default? (in this case, it would mean that it has to be closed whenever the player enters the cell)
If yes, how?!

I have a door in a cell and I want it to always startup as closed. I need to be able to make that door like that in order to reduce the number of rendered objects in the scene and hence, to reduce the lag.

Yeah, put a script on it that checks OnCellLoad() and just calls Close() (and Lock() if you want it to also be locked)

Thank you, sir.