I'm redecorating a Grade II Listed office building and have upgraded several doors with Envirograf intumescent coatings and seals, adding intumescent felt behind all ironmongery and ensuring the door closers work correctly. Being old, the hinges are heavily over-painted and probably non BS stamped (but you cannot see for sure). The hinges are all intact, firmly screwed in and have held the doors for decades.
The FRA says they all need to be BS 1154 (I think he meant BS 1935) which would mean replacing over 100 hinges. I'm not replacing any of these doors with new ones, as they having some heritage value, so is it necessary to replace these working hinges?
They need to be FD30 doors and the building is low occupancy shared office use over 2 stories with all the right fire alarms, extinguishers, signage and exits. Any guidance would be much appreciated.