Since its inception, BS 3621 has always required that a door is secure from both sides, meaning that, once locked; a key is always required to open the door, whether from the inside or the outside.
Typically BS 3621 is a standard that would be apply in a private house or small business as opposed to a public building, and is often stipulated as an insurance requirement.
Provided that the key is removed, this type of lock is secure against operation by intruders reaching through a letter-plate, breaking nearby glazing etc. Best used where emergency escape is not required or where other means of escape exist.
A BS 3621 lock will always be stamped with the British Standard 3621 Kitemark, and the lock would normally be in the form of a mortise deadlock, or a deadlocking rim type night latch lock.
A BS 3621 Kitemarked lock will have undergone vigorous testing to ensure it meets the required standard of security and protection; typically it will have the following characteristics:
In addition to BS 3621 two other more recent standards have been developed with virtually identical lock characteristics (as described above), but which are used in public buildings were fire and safety is considered more important than physical security:
Recognising that there are situations in which a keyless egress lock (secure only from the outside) can offer acceptable security, as well as safety benefits, BS 8621 was added in 2004.
Typically BS 8621 is a standard that would be apply in public buildings were fire and safety are considered more important than physical security.
BS 8621 Locks are locked by key from outside only and can always be opened from the inside without a key.
This type of lock offers emergency escape without a key at all times. Best used where there is no danger of the inside handle being operated from the outside by, for instance, breaking a glazed panel, reaching through a letter plate etc.
Finally, in 2007, BS 10621 specified a keyless egress lock with the additional feature that the escape function could be disabled, but only by a positive action, using a key from the outside, with the door closed.
Typically BS 10621 is a standard that would be apply in buildings were fire and safety are considered important, but when the building is empty say at night, the internal escape function can be locked.
BS 10621 Locks are Locked by key from outside only and can be opened from inside without a key EXCEPT when this function has been disabled by locking with a key from the outside.
Combines ease of escape in emergency with an additional security feature for use ONLY when leaving the premises unoccupied. Best used where: an alternative means of escape exists or there is no danger of the inside handle being reached from the outside.
For more information about British Standards that apply to locks contact Mr Locks your Local Merthyr Tydfil Master locksmiths free on 01685 848592. Mobile users can also call on 07976 961473. Rest assured we won't let you down!