Please could someone help me with this one.

Mum currently working on this conversion from an old registery office to 5 self contained flats over 3 stories with a basement too(bike stores)

thers is also a new extension on the side of 2 stories with a further 4 self contained flats but this also shares the same roof space as the previous building.

my question is this:

what fire alarm system do I need to have ? 

I have had various conversations with different people and still not come to any conclusion.

your expertise would be greatly appreciated 

thanks 

gavin

This should have already been specified as part of the building control process. If the works comply with Building Regulations Approved Document B for new flats there would be no need for a communal fire alarm system, just Bs5839-6 Grade D LD3 smoke alarms to each flat. As there should be smoke vents to the common areas these would need smoke detectors, but you don't need alarm sounders or call points.

If you are not following Approved Document B then you will need a more comprehensive system but without the exact detail I can't be specific.