I think with the stand alone game of DayZ they should allow you to lock doors, but they can be busted down by hostiles and zombies, but once you clear the two out, you should be able to build a barrier to stop the from coming in, temporarily. And you should be able to do the same to windows. So it would be like you can find the wood and nails and preferred guns, go to a building, and enclose yourself in the room like Black Ops Zombies. But when it gets out of hand, you can leave to the next city.
