Posted By RHOES Hi all, Can someone tell me what the maximum permitted area is for a glazing in fire door for a). door leading from an office corridor onto a protected staircase b). double doors seperating a corridor mid-way The source would be good also. I've looked at Building Regs Part B but I'm having difficulty determining the exact specification. Maybe someone a little more familiar with the guidance could help. Regards Rich

Posted By D. Hilton There isn't a limit. However, in practice the acoustic performance requirements for the door will provide a limit as this performance depends on the thickness of the glazed panel which in turn affects the safety and impact resistance of the glazing. The requirements for fire and smoke containment with respect to ‘means of escape’ are contained in Approved Document B to the Building Regulations England and Wales Safety and Impact Resistance: Approved Document N to the Building Regulations England & Wales. Acoustic Containment: Approved Document E to the Building Regulations (England & Wales) now gives specific acoustic performance requirements for door assemblies in a number of situations in "dwelling-houses, flats and rooms for residential purposes", and also in schools. Accessibility: Approved Document M to the Building Regulations England & Wales