Opening Padlock on Shabbos

A padlock that’s being used to lock a door of a building is there a problem of unlocking it and taking it off on Shabbos?

Answer:

There’s no problem with doing this on Shabbos.

Opening a padlock is no different to opening a door, which is permitted because it is not an act of construction or destruction (boneh or soter), but only of using the door in its normal manner. The same applies to a padlock, which is also made to open and close.