Hi

This is a private block of 21 flats owned by leaseholders and with their own management company. A new leaseholder has said we are legally responsible for the common area (hallway) fire Alarm to be at between 65 and 75 decibels at his bed head in his furthest bedroom with all doors closed. Are we responsible under law to ensure this? 

Firstly - has a Fire Risk Assessment been carried out by a competent person?

This (legal requirement) should answer the question (& many others) If it doesn't it's clearly not adequate.

If your premises are purpose built flats (after 1991 & often those from after 1962 as well) there isn't usually a need for a common fire alarm at all, just smoke detectors linked to smoke vents as a stay put policy is appropriate.

If your block does not have the correct compartmentation and/or smoke control provision to support stay put then a simultaneous evacuation policy is required which requires a common fire alarm that also extends into the flats with a heat detector & sounder in the hallway (certain very vulnerable very old buildings may need even more cover).

Technically the audibility should be 75dB bedhead as communal flat systems are meant to fully meet the commercial premises installation standard, however it's often been accepted (& indeed is adopted in the current official guidance for simultaneous evacuation in flats) that the residential alarm standard requirement of 85dB at the bedroom door is sufficient so the hallway sounder is enough without adding more into bedrooms.

This is of course general guidance, I'd need to visit and carry out an FRA to be specific.