This idea popped in my mind as I was barricading one of my safe house exits and didn't really want to do it because I would be essentially going to deny my way out from that direction. So the idea is wooden door latches that could be built on the inside of doors and would allow you to open them from the inside only. something that would look like this: You'd need 2-3 wooden planks and 2-4 nails to build it. It would reinforce the door as much as a normal barricade and the one plank would be removable (when opening). This could also be the only way you could lock a self made door. Now atm doors open south and east? directions so all doors wouldn't work "realistically". so that's why there could be three vertical "bars" one on each side of the door and one on the door, then you'd just place the last plank as a barricade between the bars. This way if the door opens outwards NPCs aren't able to pull it open and it's also harder for the zombies to push it in. Now I think this goes above my mod making skills for now so that's why I put it as a suggestion if someone more experienced in coding could make this happen. I wouldn't mind it in vanilla but I decided to approach it this way... I've got some clydes stashed in my crib that I could share with ya fellas... Here's a taste: