Hello - new to the forum Could anybody tell me what warrants and external fire staircase.  We have a bar for around 30 people and have secured planning for the upstairs (one flight) for a bar that will hold 25 people.  Access and egress is via the normal stairwell at the moment. Do we I need to build an external fire escape stairwell ?  

 

A number of factors determine if you need a second exit (internal or external)  including travel distances, whether the existing stair is a protected route (enclosed in fire resisting construction and fire doors with a final exit at the foot or via a protected corridor) and numbers needing to exit the storey.

Numbers wise you are OK as below 60, but the other factors still need to be accounted for.