For the purposes of paragraphs 4 and 7(a) of Schedule 2A and paragraph 2 of Schedule 2B, "household premises" means premises in which, or in any part of which, a person has his home.
The fact that a person has his home in, or in part of, any premises does not mean that the premises are household premises unless the principal use of the premises is as a home.
The Secretary of State may by regulations make provision as to—
the circumstances in which a person is or is not to be treated as having his home in, or in part of, any premises for the purposes of this section; and
the factors which are, or are not, to be taken into account in determining the principal use of any premises for those purposes.
The power to make regulations under subsection (3) above is exercisable by the Assembly (and not by the Secretary of State) in relation to premises supplied with water using the supply system of a water undertaker whose area is wholly or mainly in Wales.