When you do the math it turn out that when you factor in the labor and material for the wiring of a building the cost difference is about 20% less for NM cable. Now when it's a midrise or highrise building that's a fair piece of change. Also, NM cable is not usually the cause of fires. If NM cable causes fires more than other wiring methods maybe we shouldn't be wiring our homes with it. That's where we sleep DUH??
