Well, in suburban Portland, where the wooden shed is, the house will be similar construction. You could very, very easily drill a hole in the exterior wall, reach through the hole, and unlock the door from the inside.

In fact, in many homes (like my own), there's a window directly adjacent to the doorknob, so you could more easily just smash the glass, reach in, and unlock the door.

And yet, it's quite uncommon for that to actually happen, and not something I spend any time worrying about.

In more urban settings or higher-crime neighborhoods, of course, people take more precautions.