Hola, in a 9th floor flat that is set over two floors with the sleeping accommodation on the lower floor, is there a requirement for Fire separation between floors or can it be open plan like a lot of normal houses, except upside down, so to speak. The higher risk is upstairs in the kitchen/lounge area, which also has a fire exit directly to the protected stairwell.There is a smoke alarm in the flat connected the communal alarm and also smoke extraction on the lower floor of the flat. Many thanks

The fact it's got it's own smoke control system suggests it is a non standard (not to Approved Document B) layout mitigated by a fire engineering approach.

Layouts that are more open plan than the default approach of enclosed stairs and lobbies are not uncommon, usually using sprinklers and/or smoke control.