I have been working recently in a number of buildings which have been converted into flats from previous uses as warehouses or factories. There seems to be no pattern as to what fire alarm system is provided. Generally, compartmentation seems to be sound. Fire doors are fitted, common parts kept sterile etc. As it is often impossible to tell the date of conversion I am wondering as a general rule of thumb, what level of fire alarm system should be provided? The buildings tend to occupy 3-6 floors and anything from 10-30 flats. Should common parts have smoke detection provided? 

The guide for such premises is HOUSING – FIRE SAFETY Guidance on fire safety provisions for certain types of existing housing and includes advice on fire alarms.

Many thanks - I’ll take a look ?

But if the conversions complied with Building Regulations then https://www.local.gov.uk/sites/default/files/documents/fire-safety-purpose-built-04b.pdf is more relevant, not all conversions are non compliant and require the LACORS guide - these are usually house conversions, large scale commercial to residential conversions follow Approved Document B as a new build and so generally only require smoke detection as part of a smoke control system in common parts.

Much appreciated; thank you.