Stone fence with locked doors requires vandalism skill to either break through or lockpick the lock, so it generally provides enough protection during early stages if it looks like breaking into your base wouldn't be worth the crime.
But it's pretty much a dice roll, hoping on the mercy of your surroundings, as you can buy these skills within one day if you dedicate a character to it.
It's also ill advised because you need some sort of ambition or goal to strive towards while playing.
Aiming for a brickwall will give you a long list of tasks and goals you can tackle step by step.
