We have a strange situation - we need exclusive access to a portion of the building (i.e. exclude public from a paid venue) - but need this exclusivity to be lost in the event of the fire alarm signal, as the exclusivity boundary crosses a fire exit.

Therefore, in the event of the fire alarm signal, we wish to build in doors (which are normally inaccessible) to become automatically open, such that the public can enter the venue and exit through an approved fire exit.

Most of my research brings me to Automatic Door Closers, not Openers - and I am wondering if such a standard product exists?

Many thanks

Hi, yes, these products exist. Magnetic locks can hold your fire doors closed but will release if the fire alarm sounds. There are additional overrides available.

http://www.safelincs.co.uk/magnetic-locks/