Technical Booklet E Fire Safety·Page 38·2.11
Sleeping galleries - height and dimensions
Sleeping galleries must not exceed 4.5 m above ground level, have a floor area not exceeding 30 m², and the access stair must be within 3 m of the gallery room door. Alternative escape routes or remote emergency egress windows are required where the distance from the stair head to any gallery point exceeds 7.5 m.
Where a gallery for sleeping purposes is provided –
(a) the gallery should be not more than 4.5 m above ground level;
(b) the distance between the foot of the access stair to the gallery and the door to the room containing the gallery should be not more than 3 m;
(c) the floor area of the gallery should be not more than 30 m2;
(d) an alternative escape route, or an emergency egress window which complies with paragraph 2.9 located remote from the access stair, should be provided where the distance from the head of the access stair to any point on the gallery is more than 7.5 m;
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet E - Fire Safety.pdf