Then what about storm doors? They always swing outward and they are ubiquitous here in eastern PA, where we get a lot of snow. I have no control over what people add to their homes. I just said that we do not design homes with outswing exterior doors in areas where snow can block exiting. I often see storm doors too. Does not make it a good idea, but it is permitted. R311 in the IRC 2009 (NJ Edition) is the code reference that was originally requested in the beginning of this thread. Read IRC 311.3.1 that references direction of door swing and step-down. The problem is when there is not a step-down, and no roof over the entryway, the door can easily be blocked by snow.