Regulation 4 Key building information: use
(1)
The principal use of—
(a)
the higher-risk building,
(b)
any ancillary building,
(c)
any outbuilding,
(d)
any storey below ground level in the higher-risk building.
(2)
“Outbuilding” in relation to a higher-risk building means any permanent or temporary building, whether or not attached to the higher-risk building but not forming part of it, that is used for purposes incidental to the enjoyment of the higher-risk building.