What type of lock mechanism should be recommended for all exterior doors due to its effectiveness?

The deadbolt lock is often recommended for all exterior doors primarily because it offers a higher level of security compared to other lock mechanisms. Unlike the key-in-knob and chain locks, which can be relatively easy to bypass, a deadbolt extends deeper into the door frame, making it much more resistant to forced entry. This is due to its design that typically requires a key or thumb turn to engage and disengage the locking mechanism.

In terms of security effectiveness, deadbolts come in single and double-cylinder variations, with double-cylinder variants providing even more security by requiring a key on both sides of the door. This feature is beneficial for doors with large windows nearby, where someone might break the glass to reach inside and unlock a single-cylinder deadbolt.

The sliding bolt lock, while providing some level of security, usually does not offer the same level of resistance against forced entry as a deadbolt. Chain locks can provide a minimal level of security but are more suitable as secondary locks for added convenience rather than primary locks due to their vulnerabilities.

In summary, the deadbolt is recognized as a superior lock choice for exterior doors due to its robust design and effectiveness at preventing unauthorized access, making it the preferred option for enhancing safety and security.