Emergency egress windows in new storey habitable rooms

Each habitable room in the new storey should have – (a) an emergency egress window which complies with paragraph 2.9; or (b) an emergency egress dormer window or roof window, of the size given in paragraph 2.9 positioned as shown in Diagram 2.1, that is located to facilitate rescue from the ground by ladder. However, an emergency egress window may serve both habitable rooms provided that – (i) each room has its own access to the stairway enclosure; and (ii) it is possible to gain access, via a communicating door between the rooms, to the window without passing through the stairway enclosure.