Single-storey building definition
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), defines a single-storey building as:
'A building that consists of a ground storey only. Basements are not counted as storeys in a building (see Appendix D). A separated part that consists of a ground storey only, with a roof to which access is only provided for repair or maintenance, may be treated as a single storey building.'
Where a storey includes any of the following:
NOTE: The building is regarded as a multi-storey building if both of the following apply. |
The previous edition of the approved document gave a slightly different definition:
'A building consisting of a ground storey only. (A separated part which consists of a ground storey only, with a roof to which access is only provided for repair or maintenance…) Basements are not included in counting the number of storeys in a building.'
Where a ‘storey’ included:
- Any gallery if its area is more than half that of the space into which it projects; and
- A roof, unless it is accessible only for maintenance and repair.
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