Domestic Apartment Block - Single Staircase

[GB]

I have a 5 storey domestic apartment block with a height of 17m with 2no single level domestic apartments on each storey. The stair is lobbied at each level.

Using ADB V2 2.32 & 2.20 & 2.21 am I right in saying that there needs to be an additional stair provided or that as 2.20 if the apartments are seperated from the common stair by a lobby or corridor and the travel distance is within 7.5m from apartment exit to stair lobby, I can use a single common stair

[Phoenix]

The latter.  Single stair is ok provided the conditions of Diagram 7 and associated paragraphs are met.

Stu