Are flats are suitable for a stay put policy anyway?
Up to a point. Structure is brick built with concrete floors. There are communal extractor fan ducts which should be from bathrooms only originally but some flats might have kitchen fans put into the duct subsequently. Otherwise there should be no penetrations between flats and common areas. Ducting is steel. Ducting is in riser cupboards off stair. Bathroom fans originally had sprung fire dampers in the duct spur to each flat.
Doors to flats are ordinary uPVC or wood, not fire doors, and most flats are not lobbied.
Chance of a fire in a flat affecting both doors at the same time?
High once smoke has entered the stairwell. Doors are only about 3m apart around a corner formed by the staircase.
Common areas maintained sterile and limited sources of ignition?
Moderately so. Electrical riser cupboards (which have the fan ducts in too) have some old electrics (missing ryefield box covers etc) as well as TV amps etc. Other cupboards which are locked shut are residents' storage. Stairwell has occasional rubbish bags in (and very occasionally a motorbike!!)
It is theoretically possible for an electrical or mechanical defect to occur to prevent the door releasing, however, this is extremely unlikely and the chance of a fire occurring at the same time as a defect is in itself extremely unlikely.
Residents use the entrance door daily and would report any defects quickly; any such defects would be actioned as a priority?
Should be, building is factored by local council and the council are the majority landlord.
In the event of an electrical supply failure to the device will the locks release (fail safe to unlocked).
Not sure. The intercom control box has a battery in it - not sure if that retains the maglock.
Thanks.