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:

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.

[edit] Related articles on Designing Buildings Wiki

• Atrium definition.
• Basement v cellar.
• Floor definition.
• Multi-storey building.
• Raised floor.
• Storey.
• Suspended ceiling.
• Types of building.
• Wall types.