1005A.4 Entry doors. Entry doors and door assemblies shall comply with the following:

1005A.4.1 Locks shall be combination 1/2-inch (12.7 mm) throw deadlatch with a minimum 1-inch (25.4 mm) throw deadbolt, and so constructed that both the deadlatch and deadbolt retract simultaneously by knob or lever. The deadbolt shall have the ability to be thrown from the exterior.