You could do it with a collision box, not a bad idea at all - especially if you need to pass the door only after it’s been fully destroyed.
As soon as the door is fully destroyed, destroy the destructible component and destroy the collision that was blocking the way.
Another way to do it is to ensure it’s only the projectiles that can damage the door:
There’s also this if you wish the player to never interact with physics:
Although, it’s not 101% reliable.