Technical Booklet E Fire Safety·Page 67·2.73
Basement stairways
Single escape stairways must not serve basements. Where multiple escape stairways exist, at least one must terminate at ground level; other stairways may serve basements if protected by lobbies or corridors at each basement level.
Where an escape stairway forms part of the only escape route from an upper storey of a building (or part of a building) it should not serve a basement storey.
Where there is more than one escape stairway from an upper storey of a building (or part of a building) at least one should terminate at ground storey level. Other stairways may connect to a basement storey provided that they are protected at each basement level by a protected lobby or protected corridor.
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