Hi i am after some advice. An old victorian 4 storey, ground and 3 floors block of flats with a large central staircase is fitted with old doors, which open onto a very short corridor leading to the staircase, some glazed, some with non FR fanlights. Each flat is individually owned and not all have smoke detection. Some front doors could be considered notional fire doors. The flats are split into 2 wings and all have a 2nd fire escape with call points an alarm and smoke detection accessed from the back of each flat. Would the flats still.need to upgrade front doors to provide FR or if all flats installed smoke alarms would the secondary escape mitigate the lack of FR to the entrance doors?

Does the flats operate a a stay put or full evacuation fire procedure and was the building built to any approved standard.

Currently stay put. However all flats do not have detection and there is also a common roof void that is not double boarded but has controlled access. 

I think conversion occured in the early 70s. I am edging towards simultaneous evac and an alarm system covering common parts and flats. For stay put i would upgrade all flat doors to fd and a linked system as per lacors

I would stick to the lacors guidance, front doors to be FD30s fire doors, upgraded or replaced and a grade A in the common areas with a heat detector in the hallway of each flat. Each flat owner should be advised to provide a grade D system in each flat, not interlinked. The alternative fire escape route would be a bonus but not used as a compensatory factor for the principle means of escape.