Outside entry doors should be windowless and made of fiberglass, metal, metal clad or solid wood, not hollow core. All outside doors should have non-removable hinges and deadbolt locks with a minimum one-inch bolt. Double cylinder deadbolts (requiring a key for opening on the inside) are the most secure, but can be a serious problem in a fire.
Doors with glass windows less than 40 inches from the lock can easily be opened by breaking the glass and reaching inside. Replace the glass with unbreakable glass, or replace the door. Install a lens peephole in all outside doors, not just the front entry. Make sure peepholes are easy for all members of the family to use – including children and persons in wheelchairs.