Alternatives
Alternative locking devices can include a security screen door over the main front door, a flip lock or chain lock on the inside of the door, or a simple wedge placed at the bottom of the door.
Other Alternatives
For more advanced security, keyless locks are available. An installed keypad must have the correct code entered to allow access inside. Also, you can install sliding bar locks, which bar or lock the entire door from the inside.
Considerations
When purchasing a locking mechanism, keep in mind that though the people inside a building will be safe from outside dangers, emergencies do occur. If an emergency does occur inside, the locking mechanism needs to be simple enough to let people out of the building safely and quickly .