Technical Booklet E Fire Safety·Page 68·2.75
External escape stairs
Where multiple escape routes exist from a storey, external escape stairs may be used provided at least one internal escape stairway serves every part of each storey, and restrictions apply for Purpose Groups 2 and 5 buildings.
Where more than one escape route is available from a storey (or part of a building), one or more than one, of those routes may be by way of an external escape stair provided that – (a) there is at least one internal escape stairway from every part of each storey; and (b) in the case of – (i) a building of Purpose Group 5 – the route is not intended for use by members of the public; or (ii) a building of Purpose Group 2 – the route serves only staff accommodation (office or residential).
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