If you are purchasing a commercial building, be sure to pay attention to the egress.
Egress is the means by which occupants can exit a building. More importantly, it is how they exit during an emergency situation.
Most building types have their own regulations. For instance, the means of egress regulations may be much more strict on a multi-family building than on a warehouse.
All-in-all, the principles are the same though. There needs to be at least two means of egress from the building. That way if one way is blocked, the other can be utilized.
This is true of each floor of a building as well. Notice the picture above. There is a staircase inside the building that acts as the primary egress. But the fire escape on the side acts as the secondary egress. This means two modes of egress exist for EACH floor.
Be sure that when you buy a commercial building that it has the proper egress.