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The Dangers of Double Cylinder Deadbolts

A double cylinder deadbolt

What is a Double Cylinder Deadbolt?

A double cylinder deadbolt is a type of lock that requires a key to unlock from both the inside and outside of the door. This lock design can provide additional security to your home, as it prevents intruders from easily breaking in, especially through methods such as breaking a window and reaching in to turn the lock. However, despite these security advantages, double cylinder deadbolts also pose significant dangers.

Safety Concerns with Double Cylinder Deadbolts

One of the main dangers associated with a double cylinder deadbolt is the potential risk it poses during emergency situations.

Emergencies often require quick thinking and swift action, but with a double cylinder deadbolt, you'd need to find the key to unlock the door from the inside. In situations such as a fire, earthquake, or other urgent scenarios, this could be a daunting task and could potentially trap occupants inside. This hinders quick evacuation and poses a serious safety risk.

Non-compliance with Building Codes

Another significant downside to double cylinder deadbolts is their potential non-compliance with building codes in many areas. These codes are designed to ensure safety and accessibility, and for doors that are used as primary exits in residential buildings, easy egress is usually a requirement. Building codes often mandate that doors can be easily unlocked from the inside without the use of a key to ensure a safe and quick exit during emergencies.

Alternatives to Double Cylinder Deadbolts

If the added security of a double cylinder deadbolt appeals to you but you're concerned about the safety issues and potential building code non-compliance, there are alternative options available.

One such option is the single cylinder deadbolt. This type of lock requires a key to unlock from the outside, but it has a thumbturn on the inside that allows for easy and quick unlocking. This design offers a balance of security and safety, preventing easy entry for intruders while also ensuring that occupants can quickly exit in case of an emergency.

Another alternative is the smart lock system. These systems can be controlled remotely or unlocked with a code, providing both security and convenience. Some smart locks even offer features such as auto-lock and auto-unlock based on your proximity, and the ability to grant temporary access to visitors.

A double cylinder deadbolt


While double cylinder deadbolts can offer some advantages in terms of security, it is crucial to consider the potential dangers they pose in emergencies. Safety should always be a priority when choosing a lock system for your home. Single cylinder deadbolts and smart lock systems are safer alternatives that also provide security. Always remember to check with local building codes to ensure that your choice is compliant and safe.

Key Takeaways

- Double cylinder deadbolts, while secure, can pose a safety risk in emergencies due to the need for a key to unlock from the inside.

- Many building codes do not allow the use of double cylinder deadbolts on doors used as primary exits in residential buildings.

- Alternatives such as single cylinder deadbolts and smart lock systems offer a balance of security and safety.

- Always prioritize safety and compliance with local building codes when choosing a lock system for your doors.


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