Technical Booklet E Fire Safety·Page 172·6.21F
Floor number designation requirements
Floor numbers must follow a sequential numbering system starting from Ground Floor (or Floor 0) for the floor at mean ground level, with numbered floors above and below in sequence.
The floor number designations should meet all of the following conditions—
(a) The floor closest to the mean ground level should be designated as either Floor 0 or Ground Floor;
(b) Each floor above the ground floor should be numbered sequentially beginning with Floor 1;
(c) A lower ground floor should be designated as either Floor -1 or Lower Ground Floor;
(d) Each floor below the ground floor should be numbered sequentially beginning with Floor -1 or Basement 1.
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