Breaking down a door is generally not a Hostile Action
Hostile Actions are defined as something that directly harms another creature.
Sometimes spell effects prevent a target from using hostile actions, or the spell ends if a creature uses any hostile actions. A hostile action is one that can harm or damage another creature, whether directly or indirectly, but not one that a creature is unaware could cause harm. For instance, lobbing a fireball into a crowd would be a hostile action, but opening a door and accidentally freeing a horrible monster would not be. The GM is the final arbitrator of what constitutes a hostile action.
So, if you are simply trying to enter a building, your Sanctuary will (probably) remain intact. If you are attempting to break the door into a creature to harm it, it will not. Anything else is up to GM discretion (especially when trying to break into a building so that you can reach creatures to do harm).