Fail Safe vs Fail Secure Locks: Key Differences in Access Control

Suppose you’re overseeing a building’s security when suddenly there’s a power outage. Do the doors stay locked, trapping people inside? Or do they swing open, leaving your assets vulnerable? The type of lock you choose—fail-safe or fail-secure—could mean the difference between safety and disaster.

Many business owners and property managers ignore this important decision until it’s too late. A lock that stays closed during an emergency could trap people inside, while one that opens by default might jeopardize security. 

Without understanding the differences, you could be endangering people or assets. That’s why we put together this guide—to help you understand fail safe vs fail secure locks, how they compare and operate, and how to choose the one that best suits your needs.

What Are Fail Safe Door Locks?

Think of it like an elevator—when there’s a power failure, it stops working but has emergency measures in place to ensure safety. Similarly, fail-safe locks unlock during a power failure, so people can exit without being trapped. 

These locks remain locked as long as they receive power. During a power outage, they automatically unlock, allowing free passage. While this is safe for individuals during emergencies, it is unsafe for a building with valuables. 

For this reason, fail safe locks are generally used for main access points (like office doors or lobby), not doors for protecting assets or equipment. Furthermore, you must present a credential—such as a fob or a keycard—to open a fail safe door when there’s a power supply. 

This credential interrupts the power flow, which triggers the door to unlock. Generally, fail safe locks are used in places that prioritize life safety. Additionally, they are used with magnetic locks since they operate with a power supply.

What Are Fail Secure Door Locks?

Visualize a bank vault. When the power is cut, the vault remains securely locked, deterring unauthorized access. That’s how fail-secure locks function—they prioritize security over accessibility.

This is the opposite of the fail-safe lock. Fail secure door locks require electricity to unlock. So, the assets, equipment, and other items in that room are kept safe from damage, theft, or intruders when there’s no power. While these locks offer more security, you can override them during emergencies—they have mechanical overrides such as regular keys. 

This way, you can unlock the door and leave the building or room when power fails. However, these keys are issued to a select few such as supervisors or managers since they let people go through the door with no electronic tracking. 

Besides, sharing these keys with many people can cause confusion and complexities. Fail secure locks are typically used for IT rooms, stairwell doors, server closets, fire-related doors, and other sensitive places.

Fail Safe Vs Fail Secure

Understanding how fail-secure vs fail-safe locks compare is essential for security and safety. While one unlocks during a power failure, the other remains locked—the right one depends on your needs. Here’s how they compare.

Note: The right choice depends on whether you prioritize people’s safety (fail-safe) or asset protection (fail-secure).

Types of Locks That Can Be Fail Safe or Fail Secure

From magnetic locks to motorized or deadbolts, different lock types can be configured as either fail-safe or fail-secure. Knowing how each operates helps you make the right security decision for your building.

Magnetic Locks (Maglocks)

An armature plate and an electromagnet make up magnetic locks (maglocks). Maglocks are fail-safe since they need electric power to keep doors closed—electricity powers the magnet and locks the door. 

The armature plate is mounted on the door while the magnet is mounted on the door frame. Essentially, magnetic locks are placed at the top of the door. These locks complement glass doors, so you’ll often find them in commercial buildings and residential homes. 

Because glass doors aren’t compatible with physical locks, many architects use maglocks when drawing doors for modern offices and workspaces. Magnetic locks lack moving parts and mechanical wear, so they are durable and calm.

Electric Strikes

Typically used on wood and metal doors, electric strike locks consist of a bolt that passes through the lock and enters the strike plate mounted in the door frame. Electric strikes are usually locked by default and opened when powered. 

When you receive access, the electric strike frees a latch that unlocks the door. Unlike magnetic locks, these locks can be either fail-secure or fail-safe. Most businesses prefer them because they are generally cost-effective and easy to install in the door frame. 

The door opens instantly upon activating an electric strike, which disengages the latch. To open the door and enter, you must turn the handle after activating the electric lock.

Electromagnetic Door Holders

An electromagnetic door holder is used to hold a security or fire door open until signaled to release the metal plate to shut the door. It is also called a mag hold open or electric doorstop. This door holder includes a solid electromagnet typically placed beside the door it controls, either fixed on a wall or in a pedestal enclosure on the floor. 

The mechanism can be installed at any convenient height along the latch edge, near the floor, or at the top corner of the open door. Electromagnetic door holders are generally used on doors with high traffic. 

Compared to electromagnetic locks, an electromagnetic door holder has a weak magnetic attraction that can be manually suppressed, allowing the door to close.

Motorized Latches or Deadbolts

Motorized latches or deadbolts, used to protect external doors in commercial and residential buildings, are among the most reliable and popular types of locks. They offer high security, capable of withstanding physical attacks such as brute force and picking.

When you turn a deadbolt with a thumb or key from the inside, it pushes a bolt inside the lock cylinder. The bolt then extends into the door frame, securing the door and preventing it from opening without the correct key.

Choosing the Right Type of Lock

Choosing the wrong lock can be disastrous. Imagine a server room door opening when the power cuts, making sensitive data vulnerable. Or worse, an emergency exit staying shut during a fire. The right lock provides both security and safety, depending on your needs. Let's look at the two critical factors you should consider when choosing a security lock.

• Integrating with Emergency Systems

Opt for locks that work smoothly with your building’s emergency security systems. For fire-prone locations, choose fail-safe locks since they automatically unlock when there's a power failure, granting quick exits. 

But for high-security zones, use fail secure locks; even though they keep the doors locked when power is lost, you can manually override them with regular keys to gain access. Overall, the key is striking a balance to ensure your locks complement access control systems, emergency exits, and fire alarms.

• Hybrid Systems & Smart Access Control

Hybrid locking systems combine characteristics of both fail-safe and fail-secure mechanisms. Because these systems are flexible, they allow doors to automatically unlock or remain locked based on specific scenarios, such as fire alarms or security breaches. 

For example, a door might remain locked when power fails but unlock automatically if a fire alarm is triggered, responding to various emergencies. Smart access control systems further enhance security by integrating locks with cloud solutions. 

These systems allow remote management, real-time monitoring, and customizable access permissions. Both hybrid and smart access control systems are beneficial and critical considerations to make when selecting locks for your business.

FAQs

What is the difference between fail-safe and fail-secure?

Fail-safe locks remain locked when powered and unlock during a power failure. In contrast, fail-secure locks stay locked even when power is lost. These mechanisms serve opposite purposes.

Are mag locks fail-safe or fail-secure?

Mag locks are fail-safe. This means they require a constant power supply to stay locked, and when the power goes out, the door swings open freely for individuals’ safety and ease of egress.

How do I make my electronic locks fail secure?

Directly connect an open lock to an access control unit so that it stays locked when there’s a power outage.

What happens to the door locks when a building loses power?

When a building loses power, the door locks will either stay locked (fail secure) or unlock (fail safe). However, this depends on the system’s configuration.

Conclusion

Now that you understand the differences between fail secure vs fail safe locks, which one will you trust to protect your building? Fail safe locks are ideal for busy areas, like main entrances and inner access points. You can also use them on garage and rooftop doors. 

On the other hand, fail secure locks are typically used in places demanding high-level security, such as server rooms and rooms containing valuables. You can also apply them on doors that are not used regularly.

Fail-safe or fail-secure? Your choice could mean the difference between a safe evacuation or a security breach.