In fact, UK rules are almost identical to USA rules. Remember, these 2 countries have the most advanced rules of any country, with Canada and Australia right with them.
14.8 Means of Escape
14.8.1 Two means of escape should be provided in:-
.1 accommodation spaces used for sleeping or rest; and
.2 other accommodation spaces affected by a fire risk; and
.3 machinery spaces affected by a fire risk except:
i) those spaces visited only occasionally or unmanned during normal operation, and
where the single access gives ready escape, at all times, in the event of fire; or
ii) those spaces where any person entering and moving about the space is within 5
metres of the single entrance, at all times.
The means of escape should be such that a single hazardous event will not cut-off both
escape routes. Only in the exceptional case, such that the overall safety of the vessel would
be diminished, should means of escape contrary to Section 14.8.1.1, .2 or .3 be accepted.