Posted By Juan Carlos Arias
I suppose the purpose of the clear flaps is to prevent unintentional activation of the system by hitting the call point.

Posted By Messy Shaw
My view - indeed, my default position when completing a FRA, is that automatic detection should be avoided from common parts of flats wherever possible. (except to operate automatic smoke vents)

The building in question is described as a 'block of flats', many of which are designed with significant fire separation which may permit residents to stay in place during a fire in another flat. So does it need AFD?

Of course, those buildings with poor fire separation, including some house conversions and flats over commercial properties may need AFD.

But if there is a high likelihood of false actuations by MCP, why not consider a variation from BS 5839 and not have MCPs at all?

BS is not law and if any changes can be justified to improve safety in a specific circumstance, as long as that rationale is recorded (and reasonable), what is the problem?

After all, a building subject to regular false AFA actuations may lead to occupants completely ignoring the system or even disabling it.

So a building having multiple MCP actuations can be far more dangerous that one without any AFD at all!