Doors and Locks


(Tim Pike) #1

Many doors in office buildings incorporate swipe-cards for security which can conflict with evacuation. The acceptable solutions state that where electro-mechanical locks are present in the event of a power outage or door malfunction they are required to automatically switch to the unlocked position or be able to be easily opened without the need for a key or card etc.

There is no specific requirement to have the locks connected to the fire alarm system.

If the door lock mechanisms automatically unlock then all is fine and dandy. Evacuating people can easily pass through the door.

But if they are of the type that do not automatically unlock then there needs to be push-button over-ride that will unlock them, so that people can evacuate.

Is this really acceptable? It is OK for people to push a button (on a final exit door possibly) in order to leave?


(Robert Peart) #2

The door security override button is required to interrupt the power to the door security device so that the door fails to the unsecure state. The ability to open a door directly by an escaping occupant is absolute. You can release a door using a fire alarm in ADDITION to the emergency door release but not in place of the door release. A fire alarm panel can have the same failure modes as a security panel. An escaping occupant cannot rely on some electronic device to release a door on an escape route.
The power to secure the door must run through the emergency break glass door release. The door security must fail to an unsecure state on loss of power. Only a listed exit delay device is allowed to override this requirement.


(Biswadeep Ghosh) #3

All electronic security are required to be fitted with an Emergency Break Glass (EBG) unit which would directly interrupt the power supply to the lock.


(Geoff Merryweather) #4

While not directly related to office buildings, if you need panic bars, I don’t believe a break glass will comply, as the requirement is that you can open the door without operating hardware. If you have panic bars, the lock can’t override the panic bar, so when you operate the panic bar, the lock must drop out if not already turned off so the door can open. I am sure you can get specialist panic bars and hardware that will allow this but the architect will need to make sure they specify the correct ones, and the door lock system/ security designer will need to make sure the appropriate connections and hardware are allowed for.


(Robert Peart) #5

I’ll reword my original post.
If you decide that the ability to open a door directly by an escaping occupant is absolute then there are several downstream consequences of that decision.

Any door security in the direction of escape must be directly operable/overridden by the escaping occupant.

  1. Any door security that involves electrical power to secure the door must fail to the unsecure state on loss of power. I don’t believe that there is such a thing as a 100% reliable power supply.
  2. Any electrically secured door must have an emergency security override switch that disconnects the power supply to the door so that the door locking mechanism fails to an unsecure state.
  3. Incorporating Geoff’s comment - If panic bars are required and the doors are electrically secured then operation of the panic bars must directly disconnect the power supply to the door so that the door locking mechanism fails to an unsecure state (in addition to any mechanical locking arrangement).

The reason why fire alarm system cannot be used in place of emergency security override switches, is that fire alarm systems have many modes of failure which could result in a failure to interrupt the power supply to the electrically secure door. In other words the ability to open a secure door by activating a fire alarm system is not absolute.

I think you would be in very murky territory to step away from the absolute ability of an occupant to open a door in the direction of escape.