My front door is bulletproof but it's not your usual front door (bullet proof aside), houses here don't have fences or a big lawn in front, it's usually the garage in front and walls end to end instead of fences, so you have a wall all around your lot, some houses use those walls as well for the structure of the house (ours doesn't because it's not concrete but 100% hard wood so you need space to give it maintenance), and if they have a lawn it's usually in the back, or to the side if they have a wide lot.
Most of the houses in small or really narrow lots have a garage door facing the street, with the garage door having the main door.
So we have two front doors actually, the one in the street, and the one that goes from the garage to the actual house, the one in the actual house is usually locked, but if someone were already there it means they jumped over the street facing wall onto the roof of the garage and down into the garage, or someone left a garage door opened.