Builders cut the hole for the door, but then went home for the day. I needed a solution as I knew some damn possum would go in a make a mess, or worse, some dick over the fence might see an opportunity overnight and rob me.
All those episodes of MacGyver prepared me for this moment. A big soundproof panel I happened to have, eyebolts and ratchet straps, secured to the framing on the far side of the room