AOV requirement in the stairwell of a conversion flat with simultaneous evacuation

[Guest thelightpumpkin]

Good evening,

I want to know whether an AOV is strictly necessary in the stairwell of our victorian conversion flat. It's a tall 3 storey building with 5 flats. 

We have linked alarms and is not a 'stay put' flat. I read in a previous post on this forum that this meant an AOV is not necessary, but I wanted to check that the rules haven't since changed or there are circumstances where it is necessary.

Thanks

[AnthonyB]

Not if simultaneous evacuation is in place - one of the reasons for needing simultaneous evacuation is lack of smoke control as well as the usual compartmentation & layout. reasons.