Commentary on Sections Part 7 Section 254: Meaning of “house in multiple occupation”
576.Section 254 provides a definition of a "house in multiple occupation". To fall within that definition a privately rented building must be
	a block of flats within the meaning of section 257; or
	be subject to an HMO declaration; or
	meet one of the three tests set out in the section.
577.The standard test in subsection (2) requires that unrelated occupiers of the building share basic amenities in living accommodation that is not a self contained flat or flats, or that the living accommodation lacks one or more of those amenities. Subsection (3) provides that a self contained flat can be an HMO if unrelated occupiers share basic amenities, or the flat lacks one or more of those amenities.
578.Subsection (4) applies to private rented converted buildings which meet the shared or lack of facilities tests in (2) and also buildings that include flats where the basic amenities for the exclusive use of the occupant are located outside of the main living accommodation.
579.Section 254 also contains definitions of “self-contained flat”, “converted building” and “basic amenities”. In addition it exempts those buildings in Schedule 14 from the definition and provides regulation making powers for the appropriate national authority to amend this section and related provisions as they relate to the definition of HMO.