Thanks for all your comments guys.
There's no early warning fire detection system present and there is a dead-end corridor.
The landlord has decided to install intumescent seals and self-closers and to obtain a quote for mains wired detectors (with backup) throughout with manual break glass points at strategic points within the escape routes.
The system described above sounds like a BS5839-6 system - i.e. for residential/domestic premises. Some people will query why a commercial premises part 1 system is not being used with all the extra benefits, such as the cabling fire resistance and several other factors.
Personally I know of several smaller premises where a part 6 system, as long as it also includes the call points, has been considered a risk appropriate solution as far as fire regs are concerned, despite being at varience with British Standards.
Are the quotes just from electrical contractors or third party certified fire alarm companies?
There are some premises that have found to their cost that bunging in a few domestic heads does not a 'suitable & sufficient' means of fire warning make!
I bring the alarm up as the situation of Pt1 v Pt6 alarms was the subject of some debate on another thread